Post-anthesis stem reserve mobilization in new plant type wheat

摘要

Post-anthesis stem reserve mobilization is an important assimilate contributing source for grain filling in wheat under temperature stress conditions invariably encountered in major wheat growing regions of the world (Al-Khatib and Paulsen 1990; Blumet al. 1994). Quick screening of genetic variability in post-anthesis relative stem reserve mobilization therefore, assumes importance for developing improved wheat plant types. Post-anthesis changes in proton relaxation time T_1 of wheat stem were suggested to indicate the post-anthesis stem reserve mobilization (Pandey et al. 1998) and also genotypic differences in such mobilization under normal and one month late sown conditions (Pandey et al. 2001). It was also suggested by these authors that thick/hollow stem character, capable of superior storage and post-anthesis remobilization of assimilates may be studied for designing new plant type for increased yield potential. More recently new plant type of wheat with thick stem, improved grain weight andgrain number per ear has been developed (Singh et al. 2001). It has been suggested that physiologically these new plant type genotypes have developed an improved translocation path up to the individual floret level and an improved pre-anthesis assimilate reserve and its post-anthesis mobilization to the grain. It is in this context, the post-anthesis changes in NMR T_1 and moisture percent in the peduncle region of one of the new plant type DL 1266-5 was studied.