Four hundred and forty five genotypes of greengram were evaluated for eight quantitative traits viz. plant height, number of branches/plant, number of clusters/plant, number of pods/clusters, number of pods/plant, pod length, 100-seed weight and seed yield/plant. The data was subjected to cluster analysis, and the genotypes were grouped under three discrete clusters. This study concluded that an effective hybridization programme including the genotypes between the clusters I, II and III would produce wider segregation that might be used for development of improved greengram varieties.
Present investigation was taken up with the objective of studying the impact of biparental mating on linkage relationship among the grain quality parameters of rice. Association analysis revealed that, none of the grain quality parameters had significant positive association with grain yield except hulling parcentage in BIPs. A total of eighteen positive and significant associations in F2s and 20 positive and significant associations in F3 progenies were observed. But it was increased to 32 positive significant associations in BIPs. Like wise, negative association was also reduced in biparental progenies and it was only 10 negative associations in BIPs. But 23 negative associations in F2s and 12 negative associationsin F3 progenies were observed. It indicates that, inter correlations among the grain quality parameters were strengthened in BIPs and several new recombinants were synthesized in BIPs due to intermating in F2 population. Several such new associations were observed among the grain quality parameters in BIPs than other two segregating generations (F2 and F3 generation). It was evident that reshuffling of genes were responsible for correlations among some characters resulting newer recombinations which presumably, were due to changes from a coupling to repulsion phase linkages.
The present investigation was carried out at National Pulses Research Centre, Vamban to assess the introgression level of blackgram (Vigna mungo cv. Mash 114) genome into greengram (Vigna radiata cv. VBN(Gg)2) genome background through interspecific hybridization. Superior progenies with high yield potential and MYMV disease resistance were selected in F4 generation of cross VBN(Gg)2 and Mash 114 and evaluated in F5 generation. Based on per se and yield performance, six superior F5 progenies were selected and subjected to background analysis. A set of 84 SSR primers were surveyed and 33 SSRs were found to be polymorphic between parents. The results showed that 10.9 to 34.9 per cent of Vigna mungo genome was introgressed into Vigna radiata background. The proportion of homozygotes and heterozygotes among the progenies ranged from 5.4 to 28.8 and 7.2 to 22.2 per cent respectively. Among the six progenies surveyed, one progeny 3-10-19 recorded a maximum of 34.9% of blackgram genome. The present investigation showed the successful introgression of Vigna mungo genome into the Vigna radiata background.
Morphological traits viz., flower colour, leaf shape, seed colour and seed shape are available to distinguish the new cowpea variety VBN 3 from the ruling varieties Vamban 1, and CO(CP) 7. However, all these varieties cannot be distinguished with a single character alone. A total of 25 SSR primers were used to differentiate VBN 3 from Vamban 1 and CO(CP) 7. Among these six primers viz., CEDG156, CP09781, CEDG171, CEDG127, CEDG008 and CEDG 305 had polymorphism among varieties. Primers viz., CEDG156, CP09781, CEDG171 and CEDG008 had polymorphism between Vamban 1 and VBN 3. Likewise, primers CEDG 156, CP09781, CEDG127 and CEDG305 had polymorphism between VBN 3 and CO(CP) 7. One primer, CP09781 was able to differentiate all three varieties. Hence these primers may be useful to differentiate these varieties at DNA level. These markers will be a potent tool in seed certification.
Background: Mungbean yellow mosaic virus (MYMV) disease is the most destructive disease in blackgram. Development of MYMV resistant varieties is one of the best possible solutions to avoid the yield reduction in blackgram. There are conflicting reports on the genetics of resistance to MYMV disease claiming that it is controlled by both dominant and recessive genes. Hence the present study was aimed to understand the inheritance pattern of the MYMV disease resistance in eight crosses of blackgram.Methods: Parents, F1 and F2 generation of eight cross combinations were raised during July - Sep, 2018 at National Pulses Research Centre, Tamil Nadu Agricultural University, Vamban, Tamil Nadu. An infector row of CO 5 was raised to intensify the MYMV disease pressure after every eight rows. Based on disease incidence on 60th day after sowing, two phenotypic classes were formed among F2 plants with the scales of (1 to 3) as resistant phenotype and (4 to 9) as susceptible phenotype. The goodness of fit to Mendelian segregation ratio for MYMV disease resistance in the segregating population was tested by Chi square test (Stansfield, 1991).Result: The MYMV disease incidence was tri-genically controlled with inhibitory gene action in four crosses viz., MDU 1 x Mash 114, CO5 x Mash 114, MDU 1 x VBN 6 and CO 5 x VBN 6. Complementary gene action with two genes was observed in four crosses viz., MDU 1 x Mash 1008, CO 5 x Mash 1008, MDU 1 x VBN 8 and CO 5 x VBN 8. Differences in number of genes were observed due to the presence of recessive inhibitory gene in both male and female parents of the crosses which had complementary gene action for MYMV disease. The putative gene symbols assigned for the six genotypes viz., S1S1S2S2ii (MDU 1 and CO 5), s1s1s2s2II (Mash 114 and VBN 6) and s1s1s2s2ii (Mash 1008 and VBN 8), respectively.
Investigation was carried out with an objective of studying the genetic architecture of biparental progenies (BIPs) of JGL 384 x Rasi cross combination of rice in terms of grain quality parameters. Intermated progenies (BIPs) showed superior mean performance than their parents, F1 , F2 and F 3 generations for hulling (76.24%), milling (72.24%), head rice recovery (67.48%), kernel length after cooking (9.78), kernel L / B ratio after cooking (3.08), linear elongation ratio (1.66), volume expansion ratio (4.94) and amylose content (22.64%). Enhanced trait mean value might be due to pooling of favorable alleles through recombination, considerable heterozygosity, accumulation of favorable alleles of low frequency and breaking up of undesirable linkages which was possible because of intermating. Combining ability analysis of NCD II revealed that cooking traits like kernel length after cooking and volume expansion ratio were governed by additive genes. Hence, for the improvement of these traits pure line selection, mass selection and or progeny selection will be suggested and selection might be effective at this level. Other grain quality traits viz., hulling percentage, milling percentage, head rice recovery, kernel length, kernel breadth, kernel L/B ratio, kernel breadth after cooking, kernel L/B ratio after cooking, linear elongation ratio, breadth wise expansion ratio, gel consistency, gelatinization temperature and amylose content were governed by dominant genes. Hence, these traits could be improved by recombination breeding by taking up selection at later generations, alternatively one or two more cycles of intermating may break the undesirable linkages among the traits of interest.
An investigation was carried out at Tamilnadu Rice Research Institute, Aduthurai during Thaladi 2009 with 125 advanced breeding lines of 23 rice cross combinations to study the nature and magnitude of genetic divergence through mahalanobis D2 statistics. Observations were recorded on important panicle traits viz., panicle length, number of filled grains per panicle, panicle exertion and 100 grain weight. The breeding lines were grouped into 42 clusters. The cluster I contained highest number of genotypes (40) followed by cluster II, XXXXI, and XXXXII which had three genotypes each, the remaining 39 clusters had two genotypes each. The intra cluster distance was highest in cluster XXXXII (14.59), followed by cluster XXXXI (14.28) and cluster II (14.12). It was the lowest (0.66) in cluster III. Highest inter cluster distance was noticed between clusters XXXX and XXXV (30.35), followed by clusters XXXX and XXX (30.30), cluster XXXX and XXVIII (30.05) and lowest between clusters XIII and IV (2.04). Hundred grain weight contributes 57.67 per cent and panicle exertion contributes 19.60 per cent to the total genetic divergence. From this study it was concluded that sufficient amount of variability was observed among the breeding lines developed in the crosses viz., ADT 43/ Tapaswini, ADT 46 (R)/ IET 17917, ADT 39/ AD 02202, ADT 39/ Kalinga, ASD 19/ T 317 which may be used as parents to produce highly heterotic and superior transgressive segregants upon hybridization for important panicle traits.
Twenty one genotypes of pigeonpea were used to investigate the nature and magnitude of association of seed yield with major agronomic characters viz., plant height (cm), days to 50 per cent flowering, days to maturity, number of branches, number of pods per plant and 100 seed weight (g). This research also focussed on finding the direct and indirect effect of the various yield contributing characters on seed yield by path coefficient analysis. Correlation studies, revealed the positive and significant relationship of number of pods per plant, days to 50 per cent flowering, number of branches per plant with seed yield. The path coefficient analysis indicated that characters viz., plant height, number of pods per plant, days to 50 per cent flowering, and days to maturity should be considered as selection indices in seed yield improvement programme as they recorded high direct effects on seed yield per plant.
The mean performances of F5 progenies obtained from an interspecific cross between greengram (Vigna radiata cv (VBN(Gg)2)) and blackgram (Vigna mungo cv (Mash 114)) showed some of progenies viz., 7-6, 12-13, 12-24, 5-3 and 30-70 recorded significant superiority on seed yield per plant and also with some other yield traits too. Based on the leaf shape, the F5 progenies were grouped as lobed and ovate respectively as the green gram VBN(Gg)2 is lobed and blackgram Mash 114 is ovate to know the key component besides the superiority on yield and yield components among the segregating progenies as enormous variations were observed. The association analysis among the progenies based on the leaf shape groups revealed that the association among both the leaf group on seed yield per plant and its component traits are similar except for 100- seed weight as same as the parents. Hence the association confirmed that the variation has been governed by the blackgram genome to the green gram genome. Hence, the selection indices for ovate leaf group, emphasis should be given to 100- seed weight in addition to other traits viz., plant height, the number of branches per plant, the number of clusters per plant, the number of pods per clusters, the number of pods per plant, pod length and the number of seeds per pod. However, the selection indices for lobed leaf group to be given to all the traits except 100 – seed weight. In general, among the traits studied the first and foremost importance has to be given for the number of pods per plant, the number of clusters per plant and the number of branches per plant followed by other yield traits while framing the selection procedure for the interspecific progenies. Further selection is to be based on MYMV disease resistance and yield attributes for developing superior performing varieties among the derivatives of green gram and blackgram interspecific cross.
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