Water deficiency influence on stem elongation in wheat

Abstract

Drought is one of the most important factors limiting the wheat production worldwide. Tolerance to water stress is the basic postulate for high and stabile yields in semiarid regions. In the present study water deficiency effect on morphological characteristics of the primary stem and grain yield per spike were analyzed. Two spring (Venera, Borlaug 95) and one facultative (Nevesinjka) wheat cultivars were used as the study material. Plants were grown during two-year period (2008-2009) in pots under controlled water regime conditions. Drought effect was tested in five different treatments (I - 7 days before heading, II - at the heading time, III - 7 days after heading, IV - 14 days after heading and V - 21 days after heading). In a control treatment (IV) optimal moisture was maintained during the vegetation. The lowest value for stem height was obtained when plants were exposed to the drought in the treatment I. The maximum stem height in cv. Borlaug 95 (52.3 cm) was determined in the treatment II, in cv. Nevesinjka (45.8) in the treatment III, while in cv. Venera (47.7 cm) in the treatment V. The formation of the top internode was similar. In the cv. Borlaug 95 the maximum length of the last internode slightly varied from the treatments III to IV. There were variations in the internodes length ratio depending on the treatment. The cv. Venera has shown higher drought tolerance expressed through the higher grain production per spike.

Suša predstavlja jedan od limitirajućih faktora proizvodnje pšenice širom sveta. Tolerantnost na vodni stres, osnovni je preduslov visokih i stabilnih prinosa u aridnim i semiaridnim područjima. U radu je analiziran efekat nedostataka vode na morfološke karakteristike primarnog stabla pšenice i prinos zrna po klasu. Kao materijal za analizu poslužile su dve jare sorte (Venera, Borlaug 95) i jedna fakultativna sorta pšenice (Nevesinjka). Biljke su u dvogodišnjem periodu (2008-2009) gajene u saksijama u kontrolisanim uslovima vodnog režima. Efekat suše testiran je u 5 različitih tretmana (I - 7 dana pre klasanja, II - u vreme klasanja, III - 7 dana posle klasanja, IV - 14 dana posle klasanja i V - 21 dan posle klasanja). U kontrolnoj varijanti (VI) optimalna vlažnost održavana je tokom čitave vegetacije. Najmanja visina primarnog stabla ostvarena je kada su biljke izložene suši u I tretmanu. Najveća visina kod sorte Borlaug 95 (52.3 cm) ostvarena je u II, kod sorte Nevesinjka (45.8 cm) u III, a kod sorte Venera (47.7 cm) u V tretmanu. Na sličan način ispoljeno je i formiranje vršne internodije, pri čemu je kod sorte Borlaug 95, maksimalna dužina poslednje internodije, neznatno varirala od III do VI tretmana. Uočeno je da, u zavisnosti od tretmana, dolazi do promene odnosa dužine pojedinih internodija. Sorta Venera, pokazala se znatno tolerantnijom na vodni stres, ostvarivši veću prosečnu vrednost mase zrna po klasu pri skoro svim tretmanima.