Abstract only

Since the old times farmers have been engaged in wheat breeding for the desired traits. As a result, varieties with valuable characteristics (winter hardiness, drought tolerance, etc. ) have been developed. However, farmer-selected varieties are not high yielding enough to meet demands of the growing population at present. The farmer varieties are not input-responsive and therefore they don't fit the needs of the agricultural development, which is mostly based on high-input technologies (high fertilizer rates, modem crop management practices, etc ). The appropriate use of new achievements of the crop breeding, identification and involvement of yield-related morpho-physiological traits in the breeding process and proper selection of parental forms in crosses are the challenges to be tackled by breeders. Based on the morpho-physiological traits, Academician J.Aliev has developed a plant ideotype for wheat as a result of the long-term studies. According to J.Aliev, along with the determination of the basic traits of an ideal plant, inheritance patterns and heritability of these traits should be studied. Identification of the genes responsible for useful morpho-physiological traits in different genotypes, their transfer to improved varieties should be among the priority tasks of breeding. For this purpose, a study of the input-responsive variety Garagilchin-2 and an old variety Girmizi-bugda that sharply differ in morpho-physiological traits was carried out at the Experimental Station of of Agriculture of Azerbaijan located on the Absheron peninsula. The study was focused on the leaves of the 8th layer (flag leaf) as well as on the spike awn that play important role in grain filling process. Field experiments were carried out in two variants: under normal water provision (irrigation) and water stress. CO2 assimilation and chlorophyll content were measured during the ontogenesis. The maximum CO2 assimilation was found to occur in the flag leaf at the beginning of vegetation. The study results provide evidence that awns may be important in obtaining high grain yield. The rate of decrease of the intensity of photosynthesis under water stress in awns is lower than in the leaves (at the wax stage ). The difference between the irrigated and moisture stress treatments in the leaves and owns of Girmizi bugda were 33% and 22%, respectively, while for Garagilchin-2,33% and 28%, respectively. Chlorophyll content is determined by genotype and may vary depending on the growth stage. The study data suggest, the maximum values of chlorophyll content during ontogenesis were observed in the flag leaf at heading and flowering, while in the awns-at the stage of grain filling. This provides evidence of the important role of the awns in production of photo-assimilates during the grain filling, as well as during the moisture stresses, when the chlorophyll depression observed in leaves is much higher than in owns. Thus, according to the data results, it may be concluded that in the selection of parental material for developing high-yielding and drought-resistant varieties preference should be given to the forms with the higher numbers of awns.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection