Search

Mung bean [Vigna radiata (L.) Wilczek] is an important grain legume crop. Earlier works on micropropagation protocols for mung bean suffer from genotype dependence, poor reproducibility and insufficient regeneration efficiency. Hence, we made an attempt to develop an efficient protocol for micropropagation of mung bean cv. KM 2 using transverse thin cell layer (tTCL) system. The epicotyl, hypocotyl and nodal tTCL explants were obtained from 5-day-old seedlings and cultured on MS medium with different concentrations of BAP (6-benzylaminopurine), TDZ (Thidiazuron) and kinetin. The maximum frequency (75.25%) of direct shoot initiation and multiplication was achieved from culturing the nodal tTCL explants on MS medium containing 1.0 mg/L BAP. It has been observed that 61.4% of the regenerated shoots successfully elongated and rooted in MS medium containing 1.0 mg/L of IBA (indole-3-butyric acid) after two weeks of culture. The plantlets successfully established under greenhouse conditions with 64% survival rate. The hardened plants exhibited homogeneity and no morphological variations were detected among the regenerants and the mother plants. The identified regeneration system could be efficiently used in various in vitro manipulation studies in mung bean as well. [ABSTRACT FROM AUTHOR]

Black gram [Vigna mungo (L.) Hepper] is the third most important pulse crop in India after chickpea and pigeon pea. Soil salinity is one of the major factor responsible for loss in agricultural production. Forty eight black gram genotypes were evaluated for salt tolerance with six different salinity levels viz., EC0, EC4, EC7, EC10, EC13, EC16 at early seedling stage. All the seedling parameters and salt tolerant index were investigated from four days old seedlings. From the results, it was found that there was a gradual decrease with increasing levels of salinity in all the genotypes studied. Seed germination and dry matter production showed more variations than other parameters studied for all the genotypes at different salinity levels. Based on the results, it may be concluded that the genotypes VNBG 017, AUB 3 AND AUB 20 were saline tolerant and VNBG 022, AUB 31 AND AUB 12 were susceptible to salinity. [ABSTRACT FROM AUTHOR]

Field experiments were conducted to screen the mungbean genotypes based on root characters and root penetration ability. Observations on root and shoot characters viz., root length, shoot length, number of roots, root diameter, fresh weight of root, fresh weight of shoot, dry weight of root, dry weight of shoot, root volume, growth and yield parameters viz., plant height, number of branches, number of pods per plant, number of seeds per pod, 100 seed weight, seed yield per plant were recorded. Based on the root characters, the genotypes HUM 1, VMGG 67, VMGG 82, VMGG 83 and VMGG 90 were found to be promising. They also performed well in the field experiments. These genotypes were crossed with high yielding varieties like VBN 1, VBN 2, VBN 3 and KM 2 to get Ft Among the 20 crosses obtained, three crosses VMGG-83/VBN 2, VMGG-90/VBN 3 and VMGG-83/VBN 1 were found to perform well in F2 and they will be forwarded to next generation. [ABSTRACT FROM AUTHOR]

Investigations were carried out to study the influence of flyash seed pelleting on microbial populations of bacteria, fungi, actinomycetes, and rhizobium in black gram and green gram. The experimental results revealed that seed pelleting with fly ash seed pelleting @ 250 g with rice gruel as adhesive increased rhizobium population in black gram and fungi and actinomyctes population in green gram by 10 to 15%. Increased microbial activity will enrich soil microflora and in turn will be helpful in increasing the crop yield. [ABSTRACT FROM AUTHOR]

Five lines and four testers were crossed in a line x tester fashion resulting in twenty hybrids. Among the twenty hybrids, the two best hybrids viz., VRMGG 1 x VBN 1 and VRMGG Local x PMB 27 were selected and subjected to generation mean analysis. Among the characters studied, the parents VBN 1 and VRMGG 1 were found to be good general combiners for seed yield plant-1 and its all its related characters. Among the crosses, VRMMG 1 x VBN 1 and EC 30072 x VBN 1 exhibited the highest per se performance, hence they were selected for this study. The significance of 'C' & 'M', m, d, h, i and 1 components demonstrated the importance of both additive and dominance effects for traits among the crosses. However, the value of H was greater than D for grain yield plant-1, number of pods plant-1, seed protein content and leaf area index for both the crosses depicting the preponderance of dominance effects in their genetic control. Hence, the selection followed by hybridization in early generations was a suitable breeding method for progress in these traits. Conversely, greater value of D over H demonstrated additive nature of genes for number of branches plant-1, number of clusters plant-1, nitrate reductase activity, photosynthetic rate and stomatal conductance which advocated the utilization of pedigree for improvement of these parameters. Inter-mating or recurrent selection would be followed for genetic enhancement of grain yield in mungbean. [ABSTRACT FROM AUTHOR]

Abstract: A experiment was performed at the Experim ntal Farm, Department of Genetics and Plant Breeding, Faculty of Agriculture, Annamalai University, Chidambaram, during the period from 06 January 2010 to 08 January 2011 to observe the response of eight parents viz., LGG 450, VRMGG Local, LGG 460, EC 30072, VRMGG 1, LGG 410, PMB 27 and VBN 1 and five hybrids namely LGG450/LGG410, VRMGG Local/PMB27, LGG460/PMB27, EC30072/PMB27 and VRMGG1/VBN1 under different salt stress (control, 4 ds m-1 (deci-Siemen per meter) and 8 ds m-1). The experiment was laid out following randomized block design where each treatment was replicated three times.All biometric characters such as number of branches plant-1, number of clusters plant-1, Number of pods plant-1, 100 seed weight, seed yield plant-1 and leaf area index; biochemical characters and biophysical characters namely total chlorophyll content, nitrate reductase activity, photosynthetic rate, transpiration rate and stomatal conductance were reduced with the increase of salinity levels as compared to control. All the hybrids recorded higher levels of salinity tolerance for all the characters compared to their respective parents except for transpiration rate and stomatal conductance. Interaction effect between the genotypes and salinity levels appeared significant for most of the studied characters. From the study it can be opined that salt stress reduced all the parameters under different salinity levels. Again among the parents and hybrids, VRMGG1/VBN1 was found as relatively salt tolerant. [Copyright &y& Elsevier]

Two molecular forms, I and II (high and low molecular mass) of α-galactosidase were demonstrated in dry mung beans and a multi-step procedure was developed for isolating the tetrameric enzyme I in good yield. Two affinity chromatographic techniques were employed and an overall 10000-fold purification was achieved. The enzyme was able to catalyse the hydrolysis of α-galactosidic linkages as well as agglutinate rabbit erythrocytes (clot formation). The clot was temporary and dissolved on longer incubation, yielding free galactose. The pH optima for both activities were similar. The enzyme also destroyed human-blood-group-B activity and increased H activity. The effect of pH on Km and Vmax of the enzyme indicated the importance of carboxyl (pK ≈ 4.0) and histidine (pK ≈ 6.5) groups of activity. This was confirmed by amino acid modification experiments in the absence and presence of the substrate. The stoichiometry of enzyme inactivation showed the probable presence of 12 carboxyl groups and 9 histidine imidazole groups/molecule enzyme in the active site. The effects of modification of the groups on enzymic and hemagglutinating activities were parallel. A model explaining the display of both the activates by the enzyme, is presented in which hemagglutination is shown to be due to the formation of slightly stable enzyme-substrate complex. It is proposed that a true lectin should not alter the covalent status of the binding sugar. [ABSTRACT FROM AUTHOR]

Genetic divergence among thirty genotypes was estimated using Mahalanobis's D² statistic and total of six clusters were formed. Cluster II contained the highest number of thirteen genotypes followed by cluster I with eight genotypes and clusters V and VI contained one genotype each. The pattern of distribution of genotypes from different geographical locations into six clusters was random, demonstrating that geographical isolation may not be the only factor causing genetic diversity. The highest intra-cluster distance was observed for cluster V (17.30) and the lowest was observed for cluster I (9.52). While the highest inter-cluster distance was observed between cluster I and V (39.22). Cluster V recorded the highest mean for seed yield per plant, number of pods per plant, number of branches per plant, number of seeds per pod and 100 seed weight. Therefore, it was concluded that more emphasis should be given on cluster V for selecting genotypes as parents for crossing with the genotypes of cluster I which may produce new recombinants with desired traits. [ABSTRACT FROM AUTHOR]