Morphological and Fibre Characteristics of Gossypium arboreum L. Germplasm Lines Immune to Grey Mildew (Ramularia areola ATK.) Disease of Cotton

Abstract

A total number of 1489 Gossypium arboreum germplasm lines maintained at the CICR, Nagpur were evaluated for their reaction to grey mildew disease caused by the fungus Ramularia areola wherein 7 lines immune (no symptoms) to the disease were identified. These 7 lines namely, Bangladesh (EC 174092) and 0-135-49 belonging to race bengalense and 30805, 30814,30826,30838 and 30856 belonging to race cernuum were evaluated for various morphological attributes like leaf, flower and capsule, and the fibre quality parameters viz. 2.5% span length, fibre strength, uniformity ratio and fibre fineness for their use in crop improvement programme. The studies revealed wide variability for leaf, flower and boll characters among germplasm lines of race bengalense as well as that of race cernuum. The genotypes of race cernuum indicated high range of variability for economic characters like ginning out-turn (42.15 to 50.75%), boll weight (3.79 to 7.39 g), seed cotton yield (31.71 to 48.32 g/plant) and the fibre properties. The germplasm lines can be used as a good source of resistance for developing resistant cultivars to grey mildew in arboreum cotton.