An induced mutant, with different flower colour and stipule morphology in grass pea (Lathyrus sativus L.).

摘要

Striking variations in flower colour and shape of stipule were conspicuous in a mutant plant detected in the post-irradiated (350 Gy of gamma rays) M3 progeny of grass pea (L. sativus) cv. Bio R-231. While the parental control cultivar produced characteristic blue coloured flowers during the investigation carried out for nine consecutive years, the colour of the flower in the mutant had modified into white with blue patches on the largest petal (standard on vexillum) only. In the control, the free lateral stipules were navicular in shape with semisagittate base but the two stipules in the mutant were found to be of different shapes, one being acicular-distichous while the other was incurved with linear-fulcate shaped modification. The modified flower colour and stipule character had transmitted in the succeeding selfed generations without any alterations. The control plant was highly fertile (98.47%) but a marked increase in pollen sterility (34.71%) was noted in the mutant. The number of primary branches per plant were more or less similar but the number of pods, seeds per pod and plant seed yield decreased marginally in the mutant compared to its parental control. The mutant is true breeding and early maturing also. Meiotic studies in pollen mother cells revealed regular presence of 7II in the control but frequent occurrence of multivalent association of chromosomes at diakinesis and metaphase-I was the common feature in the mutant. Anaphasic disturbances were recorded in 19.0% cases in the form of unequal (8-6), separation (10%), laggard (5) and chromosomal bridge formation (4%) but no such irregularities could be traced in the control..