NIAB-777: AN EARLY MATURING, HIGH YIELDING AND BETTER QUALITY COTTON MUTANT DEVELOPED THROUGH POLLEN IRRADIATION TECHNIQUE-SUITABLE FOR HIGH DENSITY PLANTING

This paper describes development of mutant NIAB-777 with improved yield and fibre characters through pollen irradiation method. A cross between NIAB-78 and REBA-288 using gamma irradiated pollen at the rate of 10 Gray (Gy) of gamma rays before cross pollination was attempted. The objective was to create new genetic variability and select the desirable new cotton mutants. After irradiation followed by hybridization subsequent generations were raised to investigate the effect of irradiation treatment. Significant variations from control/parents were observed. From M1 generation, the M2 population was grown and different desirable mutants having higher yield, early maturity, resistance/tolerance to diseases were selected. These were evaluated for yield potential and desirable other economic traits in different generations till uniformity was achieved. Of these, M-7/02, later named as cv. NIAB-777 was finally selected. It produced 23.4% & 18.5% higher seed cotton yield from standards at local trials. It produced higher seed cotton yield in regional adaptability trials (17.4%), provincial coordinated cotton trials (16.6 %) and in national coordinated varietal trials (8.8 %) compared to standard cv. CIM-496. It has desirable fibre quality traits i.e. ginning out turn (GOT) of 37.6%, fibre length of 28.81 mm, fibre fineness of 4.67 µg/inch, uniformity index of 85.0%, fibre maturity 81.2% and fibre strength 91.12 thousand pounds per square inch (TPPSI). NIAB-777 is suitable for high density planting. It has better tolerance to cotton leaf curl virus (CLCuV) disease and insect pests. It is concluded that 10 Gray gamma irradiation in cotton has effectively stimulate/increase the agronomical characters and tolerance to disease.