Induced variability for nodulation characters in chickpea (Cicer arietinum L.)

Full text: The specific characteristics and the crucial activity of legume crops to fix atmospheric nitrogen is due to a symbiotic process occurring in their root nodules. It is widely accepted for their important role in sustaining crop production and soil health management. In order to explore and exploit the scope of induced mutagenesis in creating useful variability, an exhaustive experiment was conducted to make a detailed study of nodulation characters in chickpea, Nodulation behavior activity of 10 chickpea varieties having wide variation in 100 seed weight and belonging to three distinct types i.e. 4 desi (BGM-484, BGM-541, BGM-532 and KTP-1), 3 green seeded (BGM-454, BGM-469 and FM-157) and 3 kabuli (BGM-462, BGM-517 and RSG-641) were studied after they were subjected to gamma-radiation of dosage 400, 500 and 600Gy in case of desi and green seeded types and relatively lower doses of gamma-radiation i.e. 200, 300 and 400Gy in case of kabuli types along with un-irradiated control for each variety. The eight characters related to nodulation behavior studied included number of nodules, fresh weight of nodules, dry weight of nodules, nodule size, dry nodule size, biological weight, root fresh weight and root dry weight of plant to examine the variability induced by gamma-radiation. An overall range of number of nodules from 25.94 - 163.28 was recorded in the irradiated population. The range of number of nodule in desi type was observed to be 84.52 - 163.28 and the highest 163.28 was recorded in variety KTP-1 with nodule size 0.018 irradiated with 600Gy. The range observed for number of nodules in green seeded type was 52.62 to 150.08 and the highest number (150.08) was recorded in BGM-454 which was irradiated with 500Gy. Similarly, in the kabuli types the number of nodules ranged from 25.94 to 162.25 and the highest (162.25) was recorded in BGM-462 irradiated with 400Gy. The range of variability recorded in controls was much less than the irradiated population. Therefore, from the above observations it is concluded that a wide range of useful variability has been induced. Lower gamma radiation dosage induced higher the nodule number as well as higher nodule size. Similar observations recorded on other six nodulation characters indicated induction of wide variability for the nodulation character, which can be effectively isolated and utilized for further selection in M2 and M3 generations