ASHOKA RANI, YVIJAYA SANTHI, R2017-02-142017-02-142014D5084http://krishikosh.egranth.ac.in/handle/1/5810000714A field experiment was carried out at the College Farm, Agricultural College, Bapatla on vertisol soil during rabi 2012-13 to study the variation in the mineral nutrient composition of blackgram [Vigna mungo (L.) Hepper] cultivars. The experiment was laid out in Randomised Block Design with six cultivars as treatments viz., PU-31 and LBG-752 (Resistant), LBG-20 (Moderately Resistant), LBG-709 (Tolerant), LBG-645 and LBG-623 (Susceptible) in four replications. Observations were recorded on per cent incidence of YMV, morphological, physiological and biochemical parameters whitefly adult number and mineral nutrient composition before and after the incidence of YMV. Data on the yield and yield components were recorded at harvest. Yellow mosaic virus infection was noticed at 22 DAS in LBG-645 and LBG-623, at 30 DAS in LBG-709, LBG-752 and LBG-20 and at 45 DAS in PU-31. At 30 DAS, the maximum disease incidence was observed in LBG-623 (16.3%) followed by LBG-645 (8.6%) and LBG-709 (4.7%) and least in LBG-20 (2.0 %) and LBG-752 (1.6 %). At 45 DAS, the maximum disease severity was observed in susceptible cultivars (100%) followed by tolerant LBG-709 (88.8 %), resistant LBG-752 (25.5 %), moderately resistant LBG-20 (20.7) and least in resistant PU-31 (7.2%). At 60 DAS the disease severity was 10 per cent in PU-31 and 100 per cent in other cultivars. YMV infection resulted in reduction in plant height when compared with the varietal characters. The reduction in plant height was more in susceptible cultivars (10.5% in LBG-645 and 23% in LBG-623) than the other cultivars when compared with the varietal characters. In all cultivars, there was a gradual increase in the number of branches with advancement in age of the crop. Earliness in branching was observed in PU-31, but the total number of branches were more in LBG-645 and LBG-709 and less in LBG-623 than the other cultivars. When the maximum leaf area attained by the six cultivars was compared, the moderately resistant LBG-20 possessed more leaf area (26.2&98.9 %) than the susceptible cultivars (LBG-645 and LBG-623). The leaf area in PU-31 was lower than the susceptible as well as other resistant and tolerant cultivars was due to its short stature as well as short duration. The resistant and tolerant cultivars accumulated more dry matter than the susceptible cultivars. Dry matter accumulation in PU-31 was 2.4 to 4.1 folds higher than susceptible and 1.4 to 1.5 folds higher than moderately resistant and tolerant cultivars. PU-31 retained higher CGR till maturity compared to other cultivars. The maximum CGR exhibited by PU-31 was 3.6 to 4.0 per cent higher than susceptible cultivars and 1.8 to 2.8 times higher than the other resistant and tolerant cultivars. PU-31 had significantly the highest RGR during 30-45 (104 mg g-1 d-1) and 45-60 DAS (63.3 mg g-1 d-1) compared to susceptible and other cultivars. During 30-45 DAS, RGR of PU-31 was 20.5 and 37.0 per cent higher than LBG-623 and LBG-645 respectively. During 45-60 DAS, RGR in PU-31 was 1.8 to 1.9 times higher than the susceptible cultivars and 1.3 to 1.6 times higher than the other resistant and tolerant cultivars. With advancement in age NAR increased gradually in PU-31, while in all other cultivars it decreased. The NAR in PU-31 was 1.2, 1.7 to 2.0 and 4.0 to 4.7 times higher than susceptible cultivars during 15-30, 30-45 and 45-60 DAS respectively. PU-31 possessed higher (2.3 to 3.0 and 1.5 to 2.6 times) number of pods plant-1, pod weight (2.6 to 3.8 and 1.4 to 2.1 times) and seed yield ha-1 (14.7 to 17.3 and 2.2 to 3.7 times) than the susceptible and other resistant and tolerant cultivars respectively. In PU-31, pod length was 1.1 times and test weight was 1.1, 1.3 and 2.0 times higher than LBG-709, LBG-20 and LBG-645 respectively. Number of seeds pod-1 in PU-31 was 3.0, 19.5 and 57.9 per cent higher than LBG-752, LBG-709 and LBG-645 respectively and 5.8 per cent lower than LBG-20. PU-31 recorded the highest (41.1%) harvest index. Resistant and tolerant cultivars had 1.1 to 1.5 and 1.2 to 3.0 times higher chl a and chl b; 0.7 to 42.6 and 12.2 to 74.0 per cent higher carotenoids and total chlorophyll respectively than susceptible cultivars. The chl b in PU-31 was 1.5 to 3.0 and 1.2 to 1.4 times higher than susceptible and other resistant and tolerant cultivars respectively. PU-31 had higher content of carotenoid (19.7 to 42.6 % and 0.7 t0 11.6 %) and total chlorophyll (51.4 to 74.0 % and 12.2 to 38.1 %) than susceptible and other resistant, tolerant cultivars respectively. Before YMV infection LBG-623 had the highest (43.9 mg g-1) and LBG-645 the lowest (30.2 mg g-1) content of total free amino acids. After the incidence of YMV (at 60 DAS) it was higher in resistant and tolerant cultivars (98.8 mg g -1 in PU-31, 86.2 mg g -1 LBG-20 and 90.3 mg g -1 LBG-709) except LBG-752 (72.7 mg g-1) than susceptible cultivars (77.2 mg g -1 in LBG-645 and 82.2 mg g -1 in LBG-623). LBG-752, LBG-623 and LBG-645 possessed higher (376.4, 363.7 and 326.1 mg g-1 respectively) content of total soluble protein than PU-31 (173.1 mg g -1) before YMV infection. This indicates that more protein content did not resist YMV infection. The more protein content in LBG-752 and less in PU-31 indicated no relationship of protein quantity of leaves with resistance to virus infection. Protein content increased after the incidence of YMV in all cultivars upto 45 DAS and then decreased due to disease severity and advancement in age. Before the incidence of YMV total sugar content in PU-31(18.8 mg g-1) was on par with LBG-645 (17.9 mg g-1) and higher than LBG-623 (16.8 mg g-1). Later the sugar content in PU-31 highly varied with age. Whereas in other resistant, tolerant cultivars infected by YMV increase in total sugar content was observed. The differences in epicuticular wax content of leaves among the cultivars were nonsignificant. However, LBG-20 and PU-31 had higher (5.9 and 3.1 times respectively) leaf epicuticular wax content than LBG-645. In LBG-623 it was 1.5 to 2.8 times lower than PU-31 and LBG-20 respectively. The whitefly adult number per leaf in LBG-623 and LBG-645 was 1.2 to 2.4 and 1.0 to 1.8 times higher than other cultivars. Compared to LBG-623, the seed of PU-31 had lower P, Ca, Mg, S, Fe, Mn; higher K, Cu, B, N and Zn content in both the cultivars was on par. Compared to LBG-645 it had higher K, Fe, Cu, Mn, Zn, B and lower N, P, Ca, Mg, S. The ratios of N/P, K/N and K/Ca were higher and Ca/K was lower in PU-31 than susceptible cultivars. At 15 DAS compared to susceptible cultivars, in PU-31 the concentration of Ca, S, Fe and Zn was high and of N, P, K, Mg, Mn and B was low. The resistant and tolerant cultivars have lower N content and higher P content than susceptible cultivar LBG-645. The ratios of K/N, Ca/K and K/Mg were higher and N/P, N/K, K/Ca were lower in PU-31 than susceptible cultivars. At 30 DAS compared to healthy leaves of LBG-645, PU-31 had higher B content and lower content of N, P, K, Ca, Mg, S, Cu, Mn & Zn. Compared to healthy leaves of LBG-623, PU-31 had higher N, K, Ca, S, Fe, Cu, Zn and B; lower P, Mn and Mg content was on par. Compared to diseased leaves of LBG-645 healthy leaves of PU-31 had lower N, P, K, Mg, Fe, Cu, Mn and B content and higher Ca, S and Zn. Compared to diseased leaves of LBG-623, PU-31 had lower N, P, K, Mg, Cu, Mn, Zn and B and higher Ca, S and Fe. The ratios of Ca/K was higher and K/Ca was lower in PU-31 than healthy and diseased leaves of LBG-645 and LBG-623. At an age of 45 DAS compared to LBG-645, PU-31 had lower content P, K, Ca, Mg, S, Fe, Mn and B; higher Cu and Zn and on par N. Compared to LBG-623, it had higher N, lower P, K, Ca, Mg, Fe, Cu, Zn and B and on par S and Mn. The ratios of N/K, Ca/K and N/P were higher K/N, K/Ca, K/Mg were lower in PU-31 than susceptible cultivars. At an age of 60 DAS compared to LBG-645, in PU-31 the concentration of N, P, K, S, Cu was low and of Ca, Mg, Fe, Mn, B was high and Zn was on par. Compared to LBG-623, in PU-31 the concentration of N, Ca, Mg was high and of P, K, S, Cu, Zn, B was low and of Fe, Mn was on par. Compared to LBG-645, the resistant and tolerant cultivars had higher Ca and B and lower N content. The ratios of N/P, N/K, Ca/K were higher and K/N, K/Ca and K/Mg were lower in PU-31 than susceptible cultivars.en-USsowing, intercropping, wheats, tillage equipment, seed drilling, crops, mustard, fertilizers, land resources, chickpeasThesis