Seasonal Variability in Flowering Phenology in Three Natural Populations of Argania spinosa (L.) Skeels

Transcription

1 Intrnational Journal of Agricultur and Forstry 20, (4): DOI:.2/j.ijaf Sasonal Variability in Flowring Phnology in Thr Bnlahbil S. 1, Zahidi A. 2,*, Bani-Aamur F. 1, El Mousadik A. 1 1 Faculty of Scincs, Ibn Zohr Univrsity, Laboratory of Biotchnologis and Valorization of Naturals Rsourcs 2 Polydisciplinary Faculty Taroudant, Taroudant, Laboratory of Biotchnologis and Valorization of Naturals Rsourcs Abstract An xprimnt was conductd for thr conscutiv yars in thr natural populations to invstigat th ffct of sasonal climat, gographical origin and gnotyp on flowring phnology in argan. Rsults rvald that watr scarcity spcially in dry and hot yar inducd a clar rduction in flowring and fruiting lngths to 8 and 14 days. But during th rd yar charactrizd as wt following a vry humid campaign, flowring duration and fruiting lngth wr xtndd to 0 days and 00 days. Th flowring pak in th studid aras occurrd during March-April. In Ait Baha during dry yar, flowring priod was shiftd in som individuals btwn Jun-August. Undr such circumstancs, xtndd flowring sms to b a stratgy that minimizs rproductiv failur. Ait Baha sit whr th ffcts of climatic yar wr prcivd will b considrd as a mdium for slction of rsistant gnotyps to drought. Thr wr striking diffrncs among gnotyps (tr / locality) in both flowring and fruiting durations. Som individuals wr abl to produc flowrs vn in vry dry yar and can consrv th formd fruits until 2 days. Th flowring-fruiting cycl covr a priod of to 16 months dpnding on trs. For installation of orchards, improvmnt in argan rquirs slction of gnotyps with a smallr numbr of days from bloom to harvst in ordr to nsur bttr fruit production undr climatic variation of arid nvironmnts. Kywords Flowring duration, Fruiting lngth, Gnotyp, Sasonal variation, Arid nvironmnts 1. Introduction Th study of phnological aspcts of plants subjct to diffrnt sasonal changs involvs obsrvation, rcording and intrprtation of th timing of thir lif history vnts. Th phnology of lafing, flowring and fruit production in a rang of spcis and communitis wr obsrvd. Th slctiv forcs that influnc th timing of ths vnts ar discussd as phnological pattrns of ach phas (timing, frquncy, duration, dgr of synchrony, tc). Thy ar probably th rsult of compromis btwn a varity of slctiv prssurs, such as sasonal changs, rsourc availability, and th prsnc of pollinators, prdators and sd disprsrs (Johnson, 1; Mckitrick, 1; Fnnr, 18; Mdiros t al., 200; Skhwla and Yats, 200; Milla t al., 20; Bartomus t al., 20; Soudani t al., 2012). Flowring phnology can volv rapidly, as vidncd by th many xampls of phnological divrgnc btwn plant populations within th sam spcis, ach adaptd to thir local conditions. Variation in nvironmntal factors might also contribut to phnological variation in populations, but ths phnotypic plastic rsponss * Corrsponding author: dr.abdlaziz.zahidi@gmail.com (Zahidi A.) Publishd onlin at Copyright 20 Scintific & Acadmic Publishing. All Rights Rsrvd thmslvs might also b gntically modulatd to som xtnt (Quinn and Wthrington, 2002). Th priod and flowring duration ar dpndnt on th spcis (Ng and Corltt, 2000; Elzinga t al., 200). Th chang of flowring priod ovr yars has bn th subjct of svral studis (Ptanidou t al., 1; Ptanidou t al., 2014). Optimal tim for flowring is dfind as th priod of balanc btwn th intrinsic and xtrinsic factors such as th availability of pollinators and climat conditions (Wasr, 1; Johnson, 1; Eckrt and Alln, 1). As for th fruiting, it is closly linkd to flowrs production (Vara Prasad t al., 2000). Th succss of pollination dpnds on th balanc btwn th succssiv priods of flowring and sasonal activity of pollinators. Early flowring and lat flowring at th nd of th sason ar unfavorabl for succssful pollination (Kudo, 1). In argan arly flowring trs, (prcocious trs) th flowring onst occurrd in Octobr-Dcmbr (Frradous t al., 16; Bani-Aamur t al., 18). Lat flowring trs (blatd trs) start flowring in Fbruary-March; but th intrmdiat trs bloom along th humid priod of th yar. Rsult of flowring was fruit with varying productivity as wll in arly or lat-trs. Othr trs produc both typs of fruits in th sam fruiting yar. Fruits of th prcocious trs bgin to drop in lat April of th following yar. Th fruit abscission bgins in August in blatd trs. It xtnds btwn th spring and summr of th following yar in th intrmdiat argan. Th cycl of

2 0 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr flowring and fruiting xtnds ovr two yars in argan (Bani-Aamur t al., 18). Th numbr of glomruli and th numbr of flowrs pr glomrul dpnds on rainfall and tmpraturs rcordd during th flowring yar (Bani-Aamur, 2000; 2002a). Prolongd drought during th flowring sason is manifstd by a significant rduction of th fruiting branchs and numbr of fruits on twigs during th fruit ripning sason. Contribution in th phnotypic varianc of th climatic sason and tr x nvironmnt intraction wr vry significant for studid charactrs (18. and 2.%) (Zahidi t al., 201a). This bhavior towards climatic conditions varis also dpnding on tr gnotyp. Branching and shoot growth (shoot mor than two yars and fruiting branch) as wll as flowring and fruiting dpnd on rainfall btwn Dcmbr and lat March. Prcipitations aftr April did not hav dirct ffcts on th flowring in th sam yar (Zahidi, 1; Zahidi t al., 201a). Fruits productivity varid btwn 0.1 Kg (6. fruits) in dry sason in Ait Baha to 4.4 kg (228.2 fruits) during th wt sason in Argana. For othr fruit componnts, valus varid from 0.1 kg for almonds to. kg for krnls. Oil contnt in almonds varid from.2% to 44.1%, but stimatd annual yild of argan oil varid from 0.1 kg to 2.6 kg / tr (Zahidi t al., 2014a). Th multipl uss of argan, spcially th intrst of oil combind with rsistanc to drought, mak it a good candidat for domstication as a fruit tr and last dfns against dsrtification in south Morocco (Bani-Aamur and Bnlahbil, 2004; Ait Aabd t al., 20). Th fluctuation of priods of flowring and fruiting as wll as variation in numbr of trs baring flowrs and fruits dpnding on climatic conditions ar still unknown. Our objctiv was to xplor whthr th sasonal changs (.g. tmpratur and prcipitation), gographical origin affct flowring phnology and fruiting duration in argan in ordr to idntify th gnotyps with a good potntial for cultivation or for xploitation in brding programs. 2. Matrials and Mthods 2.1. Study Sit Th study was carrid out in a smi-arid and arid nvironmnt and concrnd thr natural populations followd for ovr a tn yars in svral morphological charactrs; Ait Mlloul, Argana and Ait Baha (Bani-Aamur and Zahidi, 200). Rainfalls during th thr conscutiv yars of study ar oftn scarc and variabl; taking plac mainly during th cold priod whil summr was dry. Th 1 st was dry and hot, but both yars (2 nd and rd ) wr wt, but diffrd in th distribution of sasonal prcipitation. Th yars had rlativly humid springs, whil th summr drought xtndd wll into fall (Figur 1a, b) Data Collction To xplor whthr th sasonal changs of tmpraturs and prcipitations affcts th flowring phnology and th fruiting phnology in argan; thirty trs wr randomly slctd from ach sit which wr th subjct of svral prvious studis for morphological charactrs of fruit, branching, flowr, yild and polln (Frradous t al., 16; Zahidi, 1; Bani-Aamur and Frradous, 2001; Bani-Aamur, 2002b; Zahidi t al., 201a). Trs wr slctd and taggd bfor th onst of flowring. Plants wr visitd vry twnty days btwn Sptmbr and August during th thr conscutiv yars. At ach cnsus, w notd th prsnc or absnc of flowrs in tr at diffrnt stags (Bani-Aamur, 2000). W notd also th prsnc or absnc of fruit (young fruits from flowring of th yar) or fruits during ripning drivd from flowring of th prvious yar. W considr flowring lngth (flowring duration) pr tr as th numbr of days in which flowrs ar prsnt on th tr during ach sason (autumn, wintr, spring and summr), and ach yar. Th fruiting lngth (fruiting duration) pr tr was dfind as th numbr of days in which fruits ar prsnt on plant in vry sason and vry yar. Numbr 1 was givn for th prsnc of flowr or fruit, th numbr 0 indicatd th absnc of flowr or fruit. W dducd, th numbr of trs baring flowrs or fruits pr sason, pr yar in ach sit. 2.. Data Analysis An analysis of varianc (ANOVA) in hirarchical modl with thr factors (locality, yar and tr) or four factors (locality, yar, sason and tr) was adoptd (Dagnli, 184). Tr is hirarchical to locality factor bcaus trs wr not rpatd in ach sit. Factors yar, sason and locality wr crossd. Last significant diffrnc mthod (LSD α = %) was usd for man sparation; whr significant diffrncs wr obtaind (Stl and Torri, 160; Montgomry, 184; Sokal and Rolf, 1). Gnotyps wr groupd using UPGMA (unwightd pair-group mthod arithmtic avrag). Dndrograms wr prformd on avrags of priods of flowring or fruiting pr tr. Statistic computations wr prformd using Statistix, Statitcf, NTCYS softwar (Vrsion1., Rohlf, 188).. Rsults.1. Variability of Flowring and Fruiting Lngths.1.1. According to th Yar and Locality Locality, yar and locality x yar intraction wr significant for flowring lngth and fruiting lngth (Tabl 1). During th thr yars, th avrag flowring duration was about 88 days in Ait Baha sit; 8 days in Ait Mlloul and only 8 days in Argana (Tabl 2). Th fruiting lngth was also variabl btwn th thr gographical sits during th thr yars. Th avrag fruiting duration was rspctivly 242 days in Ait Mlloul, 208 days in Argana and only 4 days in Ait Baha. In all thr sits; during th drist yar (1 st ) following a vry dry and hot campaign; th flowring

3 Intrnational Journal of Agricultur and Forstry 20, (4): durations (8 days) and thos of fruiting (14 days) wr shortr (Tabl 2). During th rd campaign charactrizd as humid following a vry wt yar (2 nd ), lngth flowring (0 days) and fruiting duration (00 days) wr longr. Intrmdiat valus wr rcordd during th scond yar, rspctivly 8 and160 days. Tabl 1. Varianc analysis for flowring lngth and fruiting duration obsrvd during th thr conscutiv yars in Ait Mlloul, Argana and Ait Baha Sourc of variation DF Man squar flowring duration fruiting duration Locality 2 68,02 ** 46,6 ** Yar 2 2, * 161,8 ** Locality x yar 4 41,2 ** 62,88 ** Tr / locality (gnotyp) 8,6 ** 2, ** Error 14,6,81 ns: not significant. *: Significant at %. : ** Significant at 1%. Tabl 2. Mans of flowring lngth and fruiting duration (x 20 days) pr yar obsrvd in th thr localitis Locality Yar 1 st 2 nd rd Avrag Ait Mlloul.20 b 4.8 a.0 a 4. a (8 days) Priods of Argana 1.46 c 2. b 4.20 a 2. b (8 days) flowring Ait Baha 1.00 c 4.6 b.20 a 4.4 a (88 days) Avrag 1.8 c (.8 days) 4.24 b (84.8 days).48 a (.6 days) Ait Mlloul.4 b.80 b 16.1 a 12.1a (242 days) Priods of Argana 8. b 8.4 b 14. a.4 b (208 days) fruiting Ait Baha 4.0 b 4. b 14.0 a. c (4 days) Avrag.4 b (146.8 days). b (.8 days) 14. a (2.8 days) Valus followd by lttrs ar significantly diffrnt (LSD %). Tabl. Analysis of varianc of flowring lngth, of fruiting duration obsrvd during th four sasons in thr conscutiv yars in Ait Mlloul Argana and Ait Baha Sourc of variation DF Man squar Flowring lngth Fruiting lngth Locality 2 1,0 ** 8, ** Yar 2 4,2 ns 60,0 * Sason 204, ** 8,4 ns Locality x yar 4,2 ns 1,2 ns Locality x sason 6 4, ns,4 ns Tr / locality 8 2, **, ** Yar x sason 6 20,4 * 4, * Locality x yar x sason 12,4 **,8 ** Tr / locality x yar 14 1,4 **,0 ** Tr / locality x sason 261 0,8 ns 1,0 ns Error 22 0, 1,2 ns: not significant. *: Significant at %. : ** Significant at 1%.

4 2 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr Tabl 4. Mans of flowring duration (x 20 days) during th four sasons according to th yar of obsrvation in th thr localitis Locality Yar Autumn Wintr Spring Summr Avrag 1 0 c 1.2 c Ait Mlloul 2 0. a 2. a ab 1.8 ab Avrag 0.2 b 1. a 1. a 0.2 b 1.0 a b 1.1 b Argana a 1.2 b a 2.2 a Avrag 0.1 c 0. ab 1. a 0.1 bc 0.6 b b 1.1 b 0.4 a 0.2 Ait Baha a 1.2 b 0.1 b a 2.2 a 0.1 b 1. Avrag 0.1 b 1. ab 2.1 a 0.2 b 1.0 a Avrag 0.2 c 1.4 b 1.8 a 0. c Valus followd by lttrs ar significantly diffrnt (LSD %). Th avrags of ach locality ar compard btwn yars. Tabl. Mans of fruiting duration (x 20 days) during th four sasons by yar of obsrvation in th thr localitis Locality Yar Sason Avrag c.1b b Ait Mlloul b 2.2 c b. a. a a Avrag 2.0 c.1 b.4 a. a.0 a c 1.6 b. a Argana b 1. b 1.8 b a. a. a.1.4 Avrag 1. c 2. b 2. b.2 a 2.6 b 1 0 c 0.8 b. a 1. b 1.0 b Ait Baha 2 0. b 0. b 1.8 b 2.8 a 1.2 b.6 a.8 a. a 2.6 a.4 a Avrag 1.4 c 1. b 2.0 a 2. a 1.8 c Avrag 1.8 c 2.4 b 2.8 a.0 a Valus followd by lttrs ar significantly diffrnt (LSD %). Th avrags of ach locality ar compard btwn yars According to Sason Locality had affctd significantly th flowring lngth and fruiting duration (Tabl ). Th flowring duration in ach sason was statistically idntical in Ait Mlloul and Ait Baha populations whil thy wr shortr in Argana locality (Tabl 4). Th fruiting lngth was longr in Ait Mlloul than thos in Argana and in Ait Baha (Tabl ). W dtctd no ffct for yar, locality x yar, locality x sason intractions for both charactrs. High sasonal variability for flowring lngth; but no ffct of sason was obsrvd for fruiting duration (Tabl ). Yar x sason and locality x yar x sason intractions wr significant for both charactrs. Flowring intnsity across th yar was xtrmly variabl, with a clar flowring pak obsrvd in wintr - spring, almost low flowring in summr and autumn. Thus, flowring duration was longr in spring (8 days) and wintr (4 days) than during autumn and summr (4 days) in Ait Mlloul population during th thr yars. In Argana, flowring duration was shortr in autumn and summr (2 days) than in spring (0 days) and wintr (18 days) (Tabl 4). At Ait Baha, th flowring lngth was shortr in summr (0.2 x 20 days) and autumn (0.1 x 20 days) than in spring (42 days) and wintr (4 days). In all thr populations, flowring duration was longr in wintr and spring of th third yar charactrizd as humid following a vry wt campaign; whil it was shortr during th two othrs yars (Tabl 4). Th fruiting lngth was longr during spring and summr than in wintr and autumn. During th dry yar, fruiting is longr during wintr and spring in Ait Mlloul sit; but was longr in spring and summr in Argana and Ait Baha (Tabl )..1.. According to Gnotyp W found a significant ffct of tr gnotyp (tr / locality) for both durations of flowring and fruiting (Tabl 1). During th thr yars, th maximum flowring lngth pr tr was obsrvd in Ait Mlloul (20 days), about 20 days longr than th maximum rcordd in Ait Baha and

5 Intrnational Journal of Agricultur and Forstry 20, (4): about 60 days than that obsrvd in Argana sit (Tabl 6). Th minimum flowring duration pr tr was about 60 days in Ait Baha. Two trs in Argana ( and 20) hav flowrs in only 20 days. Dpnding on th gnotyp, th avrag fruiting priod varis from 0 to 2 days in Ait Mlloul, and 20 days in Argana and oscillats btwn 2 and 24 days in Ait Baha. Th two trs from Argana ( and 20) hav fructifid for 214 days. Th two variabls obsrvd wr highly affctd by tr / locality (gnotyp), tr / locality x yar intraction (gnotyp x nvironmnt); howvr non of ths variabls wr affctd by tr / locality x sason intraction (Tabl ). Tr x sason intraction is highly significant in Argana and not significant in th two othr sits (Tabl 6). Whatvr th yar; flowr drop bgins btwn lat March and arly April and bcoms vry important from May to th arly summr in which almost all trs los th flowrs. During th thr yars, in Ait Mlloul all trs flowr in wintr and spring xcpt a singl tr (tr 18) that blooms in spring for only on priod (Figur 2a). Svn trs (1, 4,, 12, 20, 21 and 24) bloom in autumn and ight trs (1, 4,, 8,,, 12 and 1) in summr. In vry dry yar, watr scarcity is manifstd by a dlay in flowring which taks plac until January with th xcption of a singl tr. Th maximum was rcordd until April (Figur 2b). In vry wt yar, just aftr th first rains in Sptmbr; flowring onst occurs in autumn in four trs and rachs its maximum in March. Th sam obsrvations ar rcordd in th third yar but flowrs drop was vry intns and provs to b dlayd at th nd of April. As for th fruiting, all trs bar fruit during th yar xcpt on tr (tr ) that dos bars no fruit in autumn (Figur a). In vry dry yar, fruiting is low in autumn and intrstd a fairly small numbr of gnotyps. Th fruits wr quit young and wr th rsult of frtilization of flowrs of th prvious yar. In spring, 28 trs bar fruits that showd highr sizs. Fruit drop bgins vry arly (in April) and bcoms important in summr and only 1 trs had prsrvd fruits in August. In vry wt yar; th fruiting was important. Som trs hav simultanously two typs of fruits (young fruit from flowring of th yar and fruits from th flowring of th prcdnt yar). Falling of young fruits was quit low sinc most trs rtain fruits th following yar ( rd yar) (Figur b). Tabl 6. Analysis of varianc for flowring lngth and of fruiting duration during th four sasons in thr succssiv yars Locality Sourc of variation DF Man squar Flowring lngth Fruiting lngth Tr 2,8 **, ** Yar 2,0 ns 2, * Sason 8,2 ** 4,2 ns Ait Mlloul Tr x yar 8 1,8 ** 2, ** Tr x sason 8 0,8 ns 0, ns Yar x sason 6 2,** 1,2 ** Error 14 0, 1,1 Tr 2 1, ns, ** Yar 2,2 ns 1,1 ns Sason 42, * 2, ns Argana Tr x yar 8 1, **, ** Tr x sason 8 1,1 ** 1,1 ** Yar x sason 6 4,6 ** 1, ** Error 14 0,6 1, Tr 2 1,1 ns, ** Yar 2, ns 222,6 * Sason 2, ns 16,4 ns Ait Baha Tr x yar 8 1,1 ** 2, ** Tr x sason 8 0, ns 1,1 ns Yar x sason 6 24,1 ** 22,8 ** Error 14 0,6 1,0 DF: Dgr of frdom, ns: not significant, *: significant at %, **: Significant at 1%.

6 4 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr Tabl. Maximum, minimum and cofficint of variation for flowring lngth and fruiting duration (x 20 days) of thirty trs obsrvd in th thr localitis during th thr yars Flowring priods Fruiting priods Locality 1 st yar 2 nd yar rd yar Max Min CV Max Min CV Max Min CV Avrag maximum Ait Mlloul Argana Ait Baha Ait Mlloul Argana Ait Baha Tabl 8. Analysis of varianc for numbr of flowring and fruiting trs obsrvd during th thr yars in Ait Mlloul, Argana and Ait Baha Sourc of variation DF Man squar Numbr of flowring trs Numbr of fruiting trs Locality * 8.8 * Yar 2.6 ** 41. ** Priod ** 4.6 ns Locality x yar **.0 ** Locality x priod 2 1. ns. ns Yar x priod ** 0. ** Error ns: not significant, *: significant at %, ** significant at 1% Scond yar First yar Third yar 0.0 Prcipitations (mm) Months Ait Mlloul Argana Ait Baha Figur 1a. Data on total prcipitation pr month for th thr study yars in th thr localitis

7 Intrnational Journal of Agricultur and Forstry 20, (4): Figur 1b. Monthly tmpratur data (ovrall man, man maximal and man minimal) of th study sit Ait Mlloul during th thr yars During th thr yars in Argana, thr trs (4, and 20) bar flowrs in small amounts in all priods of obsrvation, but thy bar fruits during th four sasons (Figur 2a). All othr trs bar flowrs in spring and for a shortr priod in wintr. In summr, flowring was obsrvd in only ight trs (2,, 1, 1, 21, 22, 2 and 24) for short duration; but a singl tr () which had flowrs throughout this sason. This tr sms to b lat flowring individual in th thr localitis. In autumn, only on individual (tr 1) had flowrs; it's an arly-flowring tr and sms to ndur cold which charactrizs th Argana locality. All trs hav born fruits during th four priods of th yar with rmarkabl diffrncs, xcpt two trs ( and ) in autumn; whos fruits wr probably in rsting phas; rsumption of growth occurrd aftr th wintr rains (Figur a). In vry dry yar, watr scarcity obsrvd from Sptmbr to January and low tmpraturs in this locality wr manifstd by a fairly significant dlay in flowring which taks plac only in March with th xcption of a singl tr (Figur 2b). In wt yars (2 nd and rd ), flowring occurrd from January to Fbruary xcpt a fw individuals. Flowring pak was obsrvd in arly spring btwn March and April. Only 1/0 of trs bar flowrs in spring in th scond yar and (21/0) in th rd campaign. Th flowrs drop bgins in April; but was xtndd until July mainly in vry wt yar. For th fruiting; in vry dry yar all th trs los fruits of th prvious yar in autumn. Th rsumption of growth of th young fruits rsulting from flowring of th prvious yar taks plac in a rmarkabl way in January and rachs th maximum in April. This fruiting intrstd 26 trs only; ths fruits bcom with largr sizs. Elvn trs hav lost thir fruits until January of vry wt yar with th apparanc of young fruits from flowring of th yar. In th rd yar, th prsrvation of fruit on th tr intrstd all individuals spcially in March. Fruit drop was rlativly small compard to th othr two yars (Figur b). Ovr th thr yars, all trs bloom in Ait Baha sit. Two trs (21 and 22) hav flowrs during th four sasons. Eight trs (, 12,, 16, 21, 22, 28 and 2) bar flowrs in summr. Only four trs (20, 21, 22 and 0) in autumn and two trs (1 and 1) in wintr hav bloomd in this sit (Figur 2a). In vry dry yar, th impact of watr scarcity obsrvd from Sptmbr to January was manifstd by a low flowring which bgan in April and sprad until Jun with th xcption of a singl tr (Figur 2b). Only 20% (6/0) of trs had flowrs in Jun. In vry wt yar (2nd yar), flowring is dlayd and occurs in January and Fbruary. Flowring pak was obsrvd in Fbruary sinc 2/0 of trs had flowrs. Flowring was sprad until Jun for a limitd numbr of trs. Th sam obsrvations in th rd yar, xcpt that flowring bgan in Sptmbr for som trs. Flowring pak was obtaind btwn March and April and almost all of th trs hav flowrs in spring (2/0). Flowrs drop occurs in May and almost all trs hav lost flowrs in Jun. All trs bar fruit during th four sasons of th yar xcpt two trs (1 and 16) which hav no fruits in autumn. Ths trs hav lost all fruits by th physiological drop and th following procss of fruiting was still not functional at this sason (Figur a). In vry dry yar, all trs hav lost fruit from Sptmbr to January. Th fruiting is low and intrstd a fairly small numbr of gnotyps (/0) in wintr and (1/0) in summr. In th 2 nd yar, th drop of

8 6 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr fruits of th prvious yar continud in autumn and fruiting of th yar was quit low in wintr and spring; with th apparanc of fruits from flowrs of th yar. Fruiting rachd a pak in August 2/0 and intrstd individuals in this station. All trs that fructifid last yar hav prsrvd th fruits during autumn and wintr during th rd yar. All trs (0/0) hav born fruits in spring during this humid yar. Th fall of th larg fruits bgins in Jun and sprads until August with th apparanc of young fruits rsulting from th frtilization of th flowrs of th yar, sinc th numbr of fruiting trs incrasd from to 2 gnotyps in this sit (Figur b). According to th similarity indx (SI) of flowring duration, thr ar two groups of individuals for SI = 0. (Figur 4a). A first group contains thr individuals (tr from Ait Mlloul, 22 and 0 from Ait Baha); which bloom in four sasons for a long tim (flowring lngth 140 days and 240 days on avrag). Th scond group is dividd in an SI = 0.6 in a first subgroup containing four individuals (1, 4, 12 and 21) from Ait Mlloul, which bloom during four sasons for an avrag duration btwn 0 days and 14 days. Th scond subgroup is dividd in an SI = 0. in a first class containing a singl individual from Argana, which had flowrs during four sasons in 84 days. Th scond class is dividd in an SI = 0.8 into two subclasss; th first subclass includs 18 individuals, of which 6 % from Ait Mlloul and % from Argana, which plants flowrd across a tim from 40 days to 6 days. Th scond sub- classs is dividd in an SI = 0.80 in a subclass containing 4 individuals; 14% of thm from Ait Mlloul sit, 64% from Ait Baha and 22% from Argana. In ths individuals th flowring duration was short (0 to 40 days) and limitd from January to March. Th scond subclass includs 21 individuals from Ait Mlloul and Argana, in which flowring lngth was vry short in lss than 28 days. Ait Mlloul 2 2 G 2 21 n o 1 t 1 y p Flowring duration (x 20 days) Argana 2 2 G n o t y p Flowring duration (x 20 days)

9 Intrnational Journal of Agricultur and Forstry 20, (4): G n o t y p Ait Baha Flowring duration (x 20 days) Autumn Wintr Sping Summr Figur 2a. Flowring duration (x 20 days) for all gnotyps obsrvd in four sasons for thr succssiv yars in th sits Ait Mlloul Numbr of flowring trs Obsrvation dat Argana 21 Numbr of flowring trs Obsrvation dat

10 8 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr Ait Baha Numbr of flowring trs Obsrvation dat 1st yar 2nd yar rd yar Figur 2b. Variability in numbr of flowring trs pr yar obsrvd in Ait Mlloul, Argana and Ait Baha G n o t y p Ait Mlloul Fruiting lngth (x 20 days) G 21 1 n o 1 t y p 1 1 Argana Fruiting lngth (x 20 days)

11 Intrnational Journal of Agricultur and Forstry 20, (4): G n o t y p Ait Baha Fruiting lngth (x 20 days) Autumn Wintr Sping Summr Figur a. Fruiting lngth (x 20 days) for all gnotyps obsrvd in four sasons for thr succssiv yars in th sits Numbr of fruiting trs Ait Mlloul Obsrvation dat Argana Numbr of fruiting trs Obsrvation dat

12 260 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr Ait Baha Numbr of fruiting trs Obsrvation dat 1st yar 2nd yar rd yar Figur b. Variability in numbr of fruiting trs pr yar obsrvd in Ait Mlloul, Argana and Ait Baha Figur 4. Classification of gnotyps from Ait Mlloul (M), Ait Baha (B) and Argana (R) according to flowring (A) and fruiting lngth s (B) obsrvd during th thr conscutiv yars

13 Intrnational Journal of Agricultur and Forstry 20, (4): Flowring trs 0 0 P r c n t a g s Avrag Yars AM AR AB Fruiting trs P r c n t a g s Avrag Yars AM AR AB Figur. Prcntags of flowring and fruiting trs obsrvd in Ait Mlloul, Argana and Ait Baha during th thr yars

14 262 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr Fruits and flowrs bud in sam tim on tr Fruits from flowring of th yar Fruit of th prvious fowring Figur 6. Trs showing simultanous prsnc of flowrs of th yar, fruits from flowring of th yar and fruits from flowring of th prvious yar According to th similarity indx of fruiting lngth, thr ar two groups of individuals in an SI = 0. (Figur 4b). Th first group includs 2 individuals; 20% of thm from Ait Mlloul, 6% from Ait Baha and 1% wr from Argana sit. Thos individuals wr charactrizd by larg variability in fruiting duration btwn 66 days in tr (16) from Ait Baha to 206 days in tr () from Argana. Th scond group was dividd in an SI = 0. in two classs. Th first class includs

15 Intrnational Journal of Agricultur and Forstry 20, (4): individuals, % of individuals from Ait Mlloul, 0% originatd from Argana and 8.% from Ait Baha. Th scond class contains individuals; 6.4% from Ait Mlloul,.% from Argana and 1.% from Ait Baha with fruiting lngth across a long tims btwn 18 days in tr (6) from Argana to 28 days in tr (2) from Ait Mlloul..2. Frquncy of Flowring and Fruiting.2.1. Diffrnc btwn Localitis Locality factor is significant for th numbr of flowring and fruiting trs (Tabl 8). During th thr yars, 81% of th trs from Ait Mlloul, 0% from Argana and 6% from Ait Baha hav born flowrs. Whil 2.2% of th trs from Ait Mlloul,.% from Argana and only.6% from Ait Baha hav born fruits (Figur ) Diffrnc btwn Yars Yar and yar x locality intraction affctd significantly th numbr of flowring trs and numbr of fruiting trs (Tabl 8). Whatvr th locality, th minimum of flowring trs is obsrvd during th dry yar (1 st yar) sinc only 4.% of th trs bar flowrs. It sms that trs from Ait Baha, th most arid station, ar th most affctd sinc only 4 individuals hav blooms in short durations (Figur, 6). Th maximum of flowring trs was rcordd during th vry humid yar ( rd yar) (8.8%) and wt yar (2 nd yar) (84.%). Almost all trs hav born fruits during th rd yar (.8%); whil th numbr of fruiting trs was minimal (.8%) during th 1 st yar. During th humid yar (2 nd yar) following a dry campaign, about 8.% hav born fruits..2.. Diffrnc btwn th Priods of th Yar Th priod of yar was highly significant for th numbr of flowring trs but not significant for th numbr of fruiting trs (Tabl 8). Locality x priod intraction was not significant for both charactrs. Yar x priod intraction was highly significant for both charactrs. During th thr yars in th thr sits, most trs bloom btwn mid-january and lat May with a maximum numbr of trs in flowr btwn arly March and lat April (Figur ). At Ait Mlloul, flowring sprads ovr almost throughout th yar for both humid campaigns (2nd and rd yar) for som trs, th numbr of flowring trs rachd 0% during th most favorabl priod spcially btwn March and April. 4. Discussion Th thr sits ar in smi-arid or arid rgions of south wst Morocco, charactrizd by cold wintrs, followd by hot dry summrs. Th dry and hot sason coincids with th priod from May to bginning of Sptmbr, producing thrfor a watr dficit during lat spring and summr. Watr availability varis throughout th yar sinc th first rains bgin in Sptmbr, th latst occurring during th priod May-Jun spcially at Argana and Ait Mlloul. Th maximum tmpraturs wr rangd from 42 to 2 in August and minimum tmpratur from C to 14 C in January in Ait Mlloul. Intr-annual variability of wintr prcipitation was highr than tmpraturs xcpt th first sason (Frradous t al., 16; Zahidi, 1; Bani-Aamur and Frradous, 2001; Zahidi t al., 201b). In som spcis, sasonal variation is affcting many aspcts of cological systms, including th sasonal timing (phnology) of biological vnts. Thus, th prsnt work is an attmpt to xplor whthr th sasonal changs in tmpratur and prcipitation, affcts flowring and fruiting phnology in argan in th fild. Th rsults indicat that variability of th two traits was th fruit of influnc at diffrnt lvls of gographical origin; yar, sason of th yar, gnotyp (tr /locality) and gnotyp x nvironmnt intraction (yar x tr / locality). During th thr yars, Ait Mlloul population; shows th longst priods of flowring and fruiting wll as th numbr of trs baring flowrs or fruits than th two othrs localitis (Argana and Ait Baha). Argana sit of th High Atlas; was th wttst sit but charactrizd by a cold autumn and wintr. Th dcras of flowring lngth to only 8 days (approximatly on month in lss than in Ait Mlloul and Ait Baha) during th thr yars; was probably rlatd to th low tmpraturs that can induc a slowdown in physiological procsss of budding, branchs growth, and rproduction procss. Howvr, Ait Baha is charactrizd by its aridity, although flowring lngth was similar to Ait Mlloul with mild tmpraturs; w notic a significant rduction in priods of th prsnc of fruits on trs. Ths priods ar rducd to only 4 days (a diffrnc of 88 days). This rsult will b xplaind by high tmpraturs rlatd to hot winds (Chrgui) from th south; which may occur to 4 tims a yar as it is rportd in rfrncs and caus significant falls of fruits, flowrs and lavs (El Aboudi, ; Frradous t al., 16; Zahidi, 1). In som fruiting trs, othrs studis, rportd that high daytim tmpraturs ( 0 ) may ngativly affct flowr bud initiation and dvlopmnt and thn advrsly affct flowr quality and potntial of fruit-stting (Jackson and Hamr, 180; Caprio and Quamm, 18). Sasonal variability in tmpraturs and rainfalls spcially in dry campaign (1 st ) than in humid yars (2 nd and rd ); inducd a clar rduction in flowring duration, fruiting lngth and numbr of trs in bloom and thos with fruits. Thus, during th drist and warm yar (1st) following a vry dry campaign; flowring and fruiting lngths wr rducd rspctivly to 8 and 14 days. But in humid campaign following a vry humid yar, thos priods wr xtndd to 0 days and 00 days. Th sam ffct of drought was also rvald in th thr populations, by inducing a significant rduction in numbr of branchs with fruits and th numbr of fruits on th twigs (Zahidi t al., 201a). Th flowring-fruiting cycl covr a priod of to 16 months dpnding on trs (Bani Aamur t al., 18; Bnlahbil and Bani-aamur, 1). Thus, in cas of drought during th flowring priod, fruiting in th following sason will b lowr. Indd, during th scond yar charactrizd as

16 264 Bnlahbil S. t al.: Sasonal Variability in Flowring Phnology in Thr vry humid sinc accumulatd rainfall was about 6.6 mm in Ait Mlloul,. mm in Argana and mm in Ait Baha, but following a dry yar (rspctivly 2.,.8 and 4. mm). Th priods of flowring and fruiting wr limitd to only 8 days and 160 days. Ths rains wr bnficial in th contrary in th following yar, sinc th tim of flowring and fruiting wr rmarkabl, 2 days of flowring and days of prsistnt of fruits on th trs in addition. Th numbr of trs has incrasd also from a minimum of 4 trs with flowrs and 14 trs with fruits; to narly all th trs with flowrs and fruits in Ait Baha, th drist sit. Sprawl of flowring ovr a long priod rprsnts an additional tim which would b bnficial to incras rats of flowr visitation for ach pollinator, in obtaining pollination and ovuls frtilization; although th succss of pollination was crtainly also affctd by th spd with which ach pollinator visits flowrs (Vazquz t al., 200). W do not hav such data for our cosystm; but th longvity of th various stags of flowr in argan from floral bud opn flowr was mor than 20 days according to tr (Bnlahbil, 2004). As wll, th prsnc of fruits on trs will b in favor of fruit ripning and consquntly its oil walth, probably richnss by fatty acids.i. olic and linolic acid as rportd by Ait Aabd (201). Our finding indicatd high sasonal variability for flowring lngth and btwn sasons within th sam locality. Th full bloom priod was obsrvd in wintr spring. It varid from 18 days in wintr in Argana, to 42 days in spring in Ait Baha population. Flowring in autumn and summr was lss important and intrstd a limitd numbr of trs. Th prsnc of flowrs during th two sasons (autumn and summr) could b xplaind by th prsnc in argan of arly-trs that bar flowrs aftr th first rains of Sptmbr and Novmbr or lat-individuals who can bnfit from th lat rains rcordd in April or May as rportd by Bani-Aamur t al. (18). Most Mditrranan plant spcis prsnt a singl-pakd flowring priod in spring. Extndd flowring in othrs spcis has bn traditionally rlatd to th maintnanc of favorabl and rlativly uniform nvironmntal conditions (Ptanidou t al., 1; Bosch t al., 1; Elzinga t al., 200). This finding is clarly obsrvd in Ait Baha sit; sinc during dry yar (1 st yar), flowring priod was shiftd in som individuals btwn Jun and August instad of March-April. Undr such circumstancs, xtndd flowring sms to b a stratgy that minimizs rproductiv failur. In agrmnt, th rsults of this study suggst that Argania spinosa sms to combin wintr and spring flowring with a long priod as is th cas of svral plant spcis (Rathck and Lacy, 18). This bloom is sustaind in th summr and fall and may act as an important complmnt to th main spring rproductiv invstmnt. This intr-population and intra-population variability in flowring could b intrprtd as a bt-hdging stratgy for nduring Mditrranan unprdictabl and changing nvironmntal conditions and may maximizing th probability of pollination as rportd by Sánchz t al. (2012). In th thr populations, thr wr striking diffrncs among gnotyps (tr / locality) in both flowring and fruiting lngths. This larg variability to drought strss during was manifstd by a nt rduction in numbr of flowring trs spcially in th first yar, sinc only 26.% of trs in Ait Baha; 0% in Argana and 66.% in Ait Mlloul sit hav flowrs. But, during wt yar ( rd ) following a vry humid campaign; much than 0% and % of trs bar flowr and fruit. Ait Baha sit was th most affctd than Ait Mlloul and Argana spcially during th dry sason (1st). Ths obsrvations confirm th findings rportd by Frradous t al. (16) for th frquncy of trs baring fruits; and for fruit yild and fruits componnt (Zahidi t al., 2014). In this sit, whr th ffcts of climatic yar was prcivd will b considrd as a mdium for slction of rsistant gnotyps to drought. Considring this finding; th rproductiv stag was th most critical stag for drought strss during crop growth. This factor during rproductiv growth usually rducs yild by rducing th numbr of sds or sd siz (Viira t al., 12; D-Souza t al., 1; Brvdan and Egli, 200). Thus, in th Grn Morocco program, to crat varitis by vgtativ propagation abl to support drought conditions at last in th priphral rgions of th ara of argan and nsuring sufficint yilds; thos gnotyps hav a good potntial rgarding this charactr of drought rsistanc which can b good sourcs of grmplasm for cultivation. Som gnotyps as and 1 from Ait Mlloul;, 14 and of Argana and 1, 14 and 0 originatd from Ait Baha hav flowring priod lss than 120 days but ar abl to kp th fruit on trs for a priod mor than 160. Othrs gnotyps hav many favorabl charactristics in flowring onst, th blooming lngth, fruiting onst and fruiting duration. Thus individuals (4 and 21) from Ait Mlloul; (2, and 26) from Argana; (21 and 22) originatd from Ait Baha wr abl to produc flowrs vn in vry dry yar (1 st yar); and can consrv th formd fruits in th sam yar. Ths trs ar among individuals abl to produc mor fruiting branchs (main branchs or twigs mor than two sasons) with thr and with four or mor fruits and thrfor mor fruits (Zahidi t al., 201a). In addition, thy can produc fruits vn in sason of low productivity sinc yild can rach 21. kg (46 fruits) and about kg of almonds for oil xtraction. This productivity can rach 86.2 kg (2006 fruits) and. kg of almonds in sason highr productivity (Zahidi t al., 2014a). Both trs from Ait Baha, and som gnotyps from Ait Mlloul and Argana stand out as th most promising sinc thy can produc fruits vn in an arid nvironmnt and hav many favorabl fruit charactristics that ar commrcially important. Hnc thy can b a good sourc of grmplasm for brding of argan as a fruit tr for oil production.. Conclusions Variation in nvironmntal factors (.g. rainfall,

17 Intrnational Journal of Agricultur and Forstry 20, (4): tmpratur) contributs dirctly or indirctly to gnrat htrognity on flowring phnology in th thr studid populations. Thrfor, our finding indicatd that tmpratur and prcipitations affcts at diffrnt lvls th flowring duration, fruiting lngth, numbr of trs in bloom and numbr of trs baring fruits. Intr-population variability (diffrnc btwn localitis) was mor important than intra-population variability (diffrnc btwn trs in th sam locality). Som gnotyps showd high adaptiv plasticity spcially in Ait Baha, th dry sit. Adaptd gnotyps to climat changs in arid nvironmnts sm to b imprativ for improvmnt in argan. Irrgularity of yild is on of th main problms in fruit production. In this rgard, slction of individuals will b basd on mid to lat-bloom, which can nsur high and stabl yild undr such circumstancs and with smallr numbr of days from bloom to harvst. On othr sid, controlling cross-pollination would b ncssary to incrasd xchang of gntic information in ordr to combin th dsird charactristics. ACKNOWLEDGEMENTS W gratfully acknowldg anonymous rviwrs and offic journal which providd hlpful commnts that gratly improvd th manuscript. W thank th Morocco-Grmany Co-oprativ Projct Consrvation Projct and Dvlopmnt th argan forst (PCDA-GTZ) and th projct Pars-Agro 128 of th Morocan Ministry of Scintific Rsarch for financial support. REFERENCES [1] Ait Aabd N, El Ayadi F, Msanda F, El Mousadik A. 20. Evaluation of agro-morphological variability of argan tr undr diffrnt nvironmntal conditions in Morocco: implication for slction. Intrnational Journal of Biodivrsity and Consrvation : -82. [2] Ait Aabd N Contribution of phnotypic and molcular markrs in analysis of gntic variability of argan tr; slction for oil yild. PhD Thsis In-Scincs, Faculty of Scinc, Univrsity Ibn Zohr Agadir, 140p. [] Bani-Aamur F, Louali L, Dupuis P. 18. Maturation t chut ds fruits d l arganir. Acts d l Institut Agronomiqu t Vétérinair Hassan II. 18: [4] Bani-Aamur F Phnological phass of Argania spinosa (L. Skls) flowr. Forst Gntics. (4): 2-4. [] Bani-Aamur F, Frrradous A Fruit and ston variability in thr Argan (Argania spinosa (L.) Skls) populations. For. Gnt. 8: -4. [6] Bani-Aamur F. 2002a. Argania spinosa (L.) Skls flowring phnology. Gntic Rsourcs and Crop Evolution. 4: -1. [] Bani-Aamur F, 2002b. Variation of polln grain siz. frtility and por numbr in Argania spinosa L.(Skls) (Sapotaca). Forst Gntics. (2): 1-8. [8] Bani-Aamur F, Bnlahbil S Variation in RAPD markrs of (Argania spinosa (L.) Skls) trs and thir prognis. Forst Gntics : -42. [] Bani-Aamur F, Zahidi A Variability of laf stomatal dnsity of adult trs of Argania spinosa (L.) Skls in th fild. Acta Botanica Gallica. 2 (): [] Bartomus I, Aschr JS, Wagnr D, Danforth BN, Colla S, Kornbluth S, Winfr R. 20. Climat-associatd phnological advancs in b pollinators and b-pollinatd plants Proc. Natn. Acad. Sci. USA, 8: [] Bnlahbil S, Bani-Aamur F. 1. Pollination of th argan tr is mostly ntomophilous. In: Symposium of intrnational plant rsourcs: Argan and plants in arid and smi-arid aras. Faculty of Scincs, Agadir 2- April: pp [12] Bnlahbil S Pollinisation naturll t artificill d l arganir (Argania spinosa (L.) Skls. Doctorat EN-Scincs, Faculté ds Scincs, Univrsité Ibn Zohr, Agadir. p. [1] Bosch J, Rtana J, Crdá X. 1. Flowring phnology, floral traits and pollinator composition in a hrbacous Mditrranan plant community. Ocologia, 8 1. [14] Brvdan RE, Egli DB Short priod watr strss during sd filling, laf snscnc and yild of soyban. Crop Scinc 4: [] Caprio JM, Quamm HA. 18.Wathr conditions associatd with appl production in th Okanagan Vally of British Columbia. Can. J. Plant Sci.: [16] Dagnli P Thory and Statistical Mthods. Agricultural applications. 2nd Edition. Th Agricultural Prss A.S.B.L. Gmbloux (Blgium), pp 464. [1] D-Souza PI, Egli DB, Bruning WP. 1. Watr strss during sd filling and laf snscnc in soyban. Agronomy Journal 8, [18] Eckrt C, Alln M. 1. Cryptic slf-incompatibility in tristylous dcodon vrticillatus (Lythraca). Amr. J. Bot. 84(): [1] Elzinga JA, Atlan A, Bir A, Gigord L, Wis AE, Brnasconi G Tim aftr tim: flowring phnology and biotic intractions. Trnds Ecol. Evol. 22, [20] Fnnr M. 18. Th phnology of growth and rproduction in plants. Prspctivs in Plant Ecology, Evolution and Systmatics. 1(1): 8-1. [21] Frradous A, Bani-Aamur F, Dupuis P. 16. Stationnl climat. phnology and fruiting of th argan tr. Acts Agronomic, Vtrinary Hassan II Institut. 1(1):1-60. [22] Jackson JE, Hamr PJC Th causs of yar-to-yar variation in th avrag yild of Cox s Orang Pippin appl in England. J. Hort. Sci. : [2] Johnson S. D., 1. Climatic and phylogntic dtrminants of flowring sasonality in th Cap flora. Journal of Ecology. 81: 6-2. [24] Kudo G. 1. Rlationship btwn flowring tim and fruit st of th ntomophilous alpin shrub. Rhdodnron aurum

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