Drought tolerance in sorghum by pollen selection using osmotic stress

Abstract

A pollen selection study for drought tolerance using Poly Ethylene Glycol (PEG) as a selective agent was conducted in sorghum. Ten genotypes of sorghum suitable for post rainy season were crossed to cytoplasmic male sterile line 104A and three genotypes to 116A producing 13 hybrids. Two sets of 13 hybrids with and without pollen selection were produced. PEG at 36 per cent was applied to stigma and stylar tissue one hour before pollination for pollen selection (selective fertilization) and no treatment for control (nonselective fertilization). Hybrids thus produced through selective and non-selective fertilization were tested in moisture stress environment during post rainy season. The hybrids obtained through selective fertilization produced significantly higher mean grain yield compared to hybrids obtained through non-selective fertilization. The results indicate that selective fertilization through in vivo pollen selection using PEG as selective agent was effective in improving moisture stress tolerance of the progeny in sorghum genotypes studied. Further, the pollen selection also had influence on plant height, panicle length, panicle width, panicle weight and grain mass. Thus,the pollen selection had a significant effect on grain yield through its components and developmentally related traits. Pollen selection for osmoticstress tolerance in sorghum influences the growth and vigour of the plants resulting in superior progeny in moisture stress environment. The analysis of individual crosses indicated that pollen genotype selection was able to favour performance of the progeny. However, the pollen selection had positive effect in majority of the hybrids and the study demonstrates the transmission of the selected trait from pollen generation to progeny.