8th INTERNATIONAL WHEAT CONFERENCE

ACCumuLATIoN of PhoToSyNTheSIS ASSImILATe
IN gRAIN IN The ReComBINANT INBRed LINeS
PoPuLATIoN of WheAT deRIVed fRom CRoSS BeTWeeN
AzAR2 ANd 87zhoNg291 uNdeR dRoughT CoNdITIoN
M. Roostaei 1, 2 , S.A. Mohammadi 3 , A. Amri 4 , E. Majidi 5
and R. Haghparast 6
1 Science and Research Unit of Tehran Azad Islamic University
2 Dryland Agricultural Research, Institute (DARI), Maragheh, Iran, Tel: 00-984-212-228-
078, Fax: 00-984-212-222-069
3 Dept. of Agronomy & Plant Breeding, Faculty of Agriculture, University of Tabriz, Tabriz
51664, Iran
4 International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria
5 Agricultural Biotechnology Research Institute (ABRI), Karaj, Iran
6 Dryland Agricultural Research Institute, Sararood, Iran
E-mail Address of presenting author: roustaii@yahoo.com
Drought is one of the major abiotic stresses and average grain yield remains low, due to
drought. In order to study drought tolerance in bread wheat, 142 recombinant inbred
lines in F8 generation, derived from a cross between Azar2 (winter type) and 87Zhong291
(facultative type) was used. Experiment was conducted using randomized block design
with three replications under drought stress and supplementary irrigation during 2006-
08 seasons at Maragheh experiment station of the Dryland Agricultural Research Institute
(DARI). Studied traits included morph-physiological traits such as plant height, date
to heading, date to anthesis, date to maturity, 1000 kernel weight, grain filling relative,
dry and wet weight of spike, spike length, seed number and seed weight in spike, spiklet
number in spike and accumulation of assimilate in grain. Analysis of variance revealed
significant differences among genotypes in two experimental conditions with respect to
all the traits. Average of grain yield under drought and irrigated conditions were 928 and
2547 Kg/ha, respectively. Under drought and irrigated conditions, grain yields ranged
from 272 to 1935 Kg/ha and 1086 to 3805.4 Kg/ha, respectively. Accumulation of photosynthesis
assimilate in grain were 10.64, 24.89, 52.61 and 11.86 percentage in first, second,
third and fourth week after anthesis, respectively, under drought condition. More
than 88 percentage of photosynthesis assimilate, accumulated in the three week after of
anthesis. In the very early lines total of photosynthesis assimilate, accumulation finished
in the three week after of anthesis. Accumulation of photosynthesis assimilate in the second
and third week after anthesis has linear grain growth stage in this stage, accumulation
was the highest amount. The results indicated that traits such as date to heading,
date to anthesis, 1000 kernel weight and accumulation of assimilate in grain were very
important selection criteria for increase of yield potential under drought condition in
wheat breeding programs.
Keywords: Wheat, drought, earliness, accumulation, and photosynthesis assimilate.
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