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Pak. J. Bot., 44(4): 1363-1367, 2012.

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EVALUATION OF STEM RESERVE UTILIZATION IN PAKISTANI WHEAT GENOTYPES UNDER POST ANTHESIS CHEMICAL DESICCATION STRESS

NAYYER IQBAL*, AQSA TABASUM, AMJAD HAMEED, MUHAMMAD AKRAM, MUHAMMAD AFZAAL AND RUBINA ARSHAD

Abstract: Pre-anthesis assimilation of stem reserves is considered as an important source for grain filling during post anthesis abiotic stresses that inhibit photosynthesis. Twenty one Pakistani wheat genotypes were evaluated for stem reserve utilization (SRU) using potassium iodide (0.4%) induced desiccation stress 14 days after anthesis. Evaluated genotypes differed significantly (p<0.01) for percent reduction in kernel weight under chemical desiccation stress. Percent reduction in kernel weight ranged from 26.19% to 50.72%. Minimum reduction was observed in C-271 (26.19%) showing highest stem reserve utilization while maximum reduction in kernel weight was recorded in Maxi-Pak (50.72%) presenting least SRU. A significant negative correlation (R²=0.452) between percent reduction in kernel weight and plant height was observed. In conclusion, tested genotypes vary considerably in stem reserve utilization when subjected to post-anthesis chemical desiccation inhibiting the photosynthesis. The genotypes with better SRU based kernel growth in the absence of photosynthesis may also provide relative tolerance to drought. This technique therefore, can be used to indirectly screen the wheat genotypes for better performance under terminal drought conditions.

Nuclear Institute for Agriculture and Biology (NIAB), P.O. Box 128, Jhang Road, Faisalabad, Pakistan

*Corresponding author e-mail: iqbalnayyer@hotmail.com