Abstract
This paper describes about cotton mutant NIAB-846 developed through pollen irradiation technique with improved yield and
fibre quality parameters. A cross was attempted between NIAB-78 (local variety) and REBA-288 (an exotic line) at NIAB.
The pollen used for crossing was irradiated @10 Gy (Grey) of gamma rays before cross pollination. The objective of induced
mutations through pollen irradiation was to develop new germplasm and select new cotton mutants having desirable traits.
The M2 population was raised using M1 seeds and mutants with better yield, earliness, resistance/tolerance to diseases and
insect pests were selected. The selected mutants were evaluated for higher yield and yield contributing traits in different
generations (M3-M6). Significant variations compared to parents were observed in evaluated mutated generations. Among
the selected mutants, M-46/02 later named as NIAB-846 was finally selected for field performance evaluation. It produced
32.2% higher seed cotton yield compared to standard CIM-499 and CIM-496 at NIAB local trials. In regional adaptability
trials in different zones of Punjab, it produced 22.4% higher seed cotton yield than standards. Whereas, in provincial
coordinated cotton trials (PCCT) and in national coordinated varietal trials (NCVT), it produced 7.0 % and 8.0 % higher seed
cotton yield respectively compared to standards. At Punjab locations it produced higher seed cotton yield than standard and
ranked 4th in yield over all the candidate lines. On an average of all trials, NIAB-846 produced 18.9 % higher seed cotton
yield. The mutant NIAB-846 has desirable fibre quality traits i.e. ginning out turn (GOT) 38.49%, fibre length 29.80 mm,
fibre fineness 4.67 µg/inch, uniformity index 85.5%, fibre maturity 83.0% and fibre strength 96.1 thousand pounds per square
inch (TPPSI). NIAB-846 is high yielding, early maturing with desirable plant type. It has sympodial type with one to two
fruit bearing monopodia, desirable foliage and medium stature. It has better tolerance to cotton leaf curl virus-burewala strain
(CLCuV-B) disease and insect pests. It is maintained and breeder nucleus seed (BNS) provision to farmers is in progress.
From these results it is concluded that low dose pollen irradiation technique in cotton is effectively used to enhance/increase
the different yield and yield contributing traits, fibre quality and tolerance to diseases in cotton. This technique is also proved
to be economical as compared to transformation/transgenic procedures for plant improvement.
