Mutagenesis in Guar [Cyamopsis tetragonoloba (L.) Taub.]

摘要

Guar or clusterbean [Cyamopsis tetragonoloba (L.) Taub.] (2n=14) is a multipurpose legume crop, grown for feed, green fodder, vegetable, green manuring, and grain purposes. Mutagenesis is a powerful tool for creating variation in a crop like guar where exploitable and favourable genetic variability is very meager. Various types of manifestations such as reciprocal translocations, trisomies, reduction in seed germination, seedling survival, pollen fertility, seed yield, number of seeds per pod, and pod length have been reported in the materials treated with mutagens and their progenies. Additionally, some researchers have observed increase in peduncle length, plant height, and number of clusters, number of pods per cluster, number of pods, seed yield, protein content, gum content and early maturity in the mutated material. The doses of 100 to 200 kR have been quoted to be lethal. The application of chemical mutagens like EMS, hydroxyl amine, hydrazine hydrate, ki-tazin, saturn, sodium nitrate, NMU,and sodium azide have generated chlorophyll mutations, profuse vegetative growth, single stem, regular pod bearing, changed leaf texture or shape and pod size, late flowering, changes in seed colour, determinate and spreading growth habit etc. Heterophylly in guar has also been reported. The effect of hybridization and mutagenesis on the inheritance of various morphological traits in guar has also been studied. Further research and understanding on mutation induction is needed to generate more desirable genetic variability for traits of economic importance to develop better ideotypes in guar.