Implications of hybrid vigour, combining ability and per se performance in pigeonpea [Cajanus cajan (L.) Millsp.]

Three CGMS lines were crossed with 17 testers in a line × tester design during Kharif 2013 and sufficient number of hand pollinated seeds was produced. The resultant 51 hybrids along with their 20 parents and standard check variety (Maruti) were evaluated in RBD design with two replications. Combining ability analysis evinced predominance of non-additive gene effects for 7 characters indicating relevance of heterosis breeding for improving yield attributes. The gca effects of parents revealed that ICPA-2043, GRG-2009, GRG-2009-2, LAXMI, LRG-41 and JKM-197 were good general combiners for seed yield and it’s direct components. The estimates of sca effects revealed that 11 experimental hybrids had significant, desirable and positive sca effects for seed yield/plant. Among these, three best crosses were selected on the basis of per se performance for ascertaining their association with sca effects of seed yield per plant and its attributes. The investigation identified the good general combiners (ICPA -2043, GRG-2009, GRG-2009-2, LAXMI, LRG-41 and JKM-197) and promising crosses (ICPA-2043 X GRG-2009-2, ICPA-2047 X GRG-2OO9 and ICPA-2043 X ICPL-288) showing high mean and significant positive sca effects involved high × high gca effects of parents. These parental combinations may be used in breeding program for exploitation of hybrid vigour

Assessment of per se performance, combining ability, hybrid vigour and reaction to major diseases in pigeonpea [Cajanus cajan (L.) Millsp.]

An experiment was carried out using seven cytoplasmic-genetic male sterile (CGMS) lines as females and seven diversified testers as males in a line × tester design. The analysis of variance for parents, females x males, hybrids and parents vs hybrids showed significant differences for almost all characters studied indicating the presence of sufficient variability among parents. Analysis of variance for combining ability revealed that mean squares due to females and line x tester interaction were significant for most of the characters. Thereby it is suggested that the variation in hybrids in respect of seed yield may be strongly influenced by the female lines. Analysis of variance revealed that the ratio of variance due to GCA to SCA was less than unity for all the characters indicating that these traits may be under the influence of non additive gene action and these characters are more likely to be improved through heterosis breeding. The gca effects of parents revealed that ICPA-2043, ICPA-2047, ICPA-2078, AKT-9913, BDN-2 and GRG-811 were good general combiners for seed yield and it’s direct compo-nents. The top three crosses exhibiting high specific combing ability effects along with their Per se performance, standard heterosis and gca status of the parents indicated that the cross combinations ICPA-2092 x GRG-811, ICPA-2043 x ICP-7035 and ICPA-2047 x RVKP-261 were good specific combiners for seed yield. These parental combinations are being used for exploitation of hybrid vigour. The good general combiners (ICPA-2043, ICPA-2047, ICPA-2078, AKT-9913, BDN-2 and GRG-811) and promising crosses viz. ICPA-2047 x GRG-811 and ICPA-2047 x BDN-2 were resistant for SMD and Fusarium wilt diseases, having high mean performance, positive sca effects for seed yield were identified from the present investigation and these may be useful in future breeding program

Correlation and path analysis in recombinant inbred lines (RILs) of wheat (Trticum aestivum L.)

Correlation and path coefficient analysis were studied in 22 heat tolerant Recombinant Inbred Lines (RILs) of wheat. Analysis of variance revealed the significant difference among genotypes for all the characters. Suggested that there was ample scope for selection of promising RILs for yield improvement. A wide range of variability was exhibited by most of the traits. The results of correlation studies indicated that genotypic correlation coefficients were higher in magnitude than their corresponding phenotypic correlation coefficients for all the traits which indicated that association among these characters was under genetic control and indicating the preponderance of genetic variance in expression of characters. Grain yield per plant had high, significant and positive association with number of grains per spike, spike weight, spike length, canopy temperature depression, tillers per plant, grain filling period and chlorophyll content both at genotypic and phenotypic levels indicating that these traits were main yield attributing traits. Path analysis revealed that grains per spike, tillers per plant, spike length, had the highest positive direct effect on grain yield followed by flag leaf length, flag leaf width, days 50% heading, plant height, grain filling period, membrane stability and days to maturity at genotypic level. The selection of characters such as grains per spike, tillers per plant, spike length and spike weight would be helpful for further improvement in RILs of wheat

G x E Interaction and path analysis for yield and its attributing traits in advanced genotypes of pigeonpea [Cajanus cajan (L.) Millsp.]

The present investigation was carried out during kharif-2012, 2013 and 2014 under rain fed condition at the Agricultural Research Station, Kalaburagi located in north eastern dry zone (Zone 2) of Karnataka, to know the stability and path analysis of the twenty genotypes of pigeonpea including check WRP-1. Highly significant differences among genotypes were observed for all the characters except primary branches. Environmental + (Genotype × Environment) interaction was significant for days to maturity, primary branch, pod bearing length, and seed yield per plant. The variance due to pooled deviation was highly significant for all the characters except for primary branches, pod length and number of seeds per pod which reflect the presence of sufficient genetic variability in the material. Out of 20 genotypes studied, RVK-275 (X=38.713, bi=1.7 and S2di = -9.67) and AKT-9913 (X =43.397, bi=2.86 and S2di= -7.42) were found to be a stable for seed yield and test weight, across the environments with good stability under rain fed conditions compared to local check. Path analysis revealed that days to flower initiation (3.942 and 1.123), days to maturity (1.493 and 0.960), primary branches (0.667 and 0.045), pod bearing length (1.153 and 0.394), number of pods per plant (0.661 and 0.463) and 100 seed weight (0.352 and 0.426) had the highest positive direct effect on grain yield both at genotypic and phenotypic level. For maximizing the grain yield per plant emphasis should be given in selection of such characters for further improvement in pigeonpea

Recruitment of CD16+ monocytes into synovial tissues is mediated by fractalkine and CX3CR1 in rheumatoid arthritis patients

CD16+ monocytes, identified as a minor population of monocytes in human peripheral blood, have been implicated in several inflammatory diseases, including rheumatoid arthritis (RA). Fractalkine (FKN, CX3CL1), a member of the CX3 C subfamily, is induced by pro-inflammatory cytokines, while a receptor for FKN, CX3CR1, is capable of mediating both leukocyte migration and firm adhesion. Here, we investigated the role of FKN and CX3CR1 in activation of CD16+ monocytes and their recruitment into synovial tissues in RA patients. High levels of soluble FKN were detected in the synovial fluid and sera of RA patients. Circulating CD16+ monocytes showed a higher level of CX3CR1 expression than CD16- monocytes in both RA patients and healthy subjects. High level expression of CX3CR1 was also seen in CD16+ monocytes localized to the lining layer in RA synovial tissue. In the in vitro culture experiments, IL-10 induced CX3CR1 expression on the surface of monocytes, and TNFalpha induced membrane-bound FKN as well as soluble FKN expression in synovial fibroblasts. Moreover, soluble FKN was capable of inducing IL-1beta and IL-6 by activated monocytes. These results suggest that FKN might preferentially mediate migration and recruitment of CD16+ monocytes, and might contribute to synovial tissue inflammation.</p

Molecular dissection of genetic diversity in pigeonpea [Cajanus cajan (L) Millsp.] minicore collection

The present investigation was carried out using 191genotypes as mini core collections of pigeonpea along with 5 check varieties to know the genetic diversity at molecular level. Significant variation was observed by the way of analysis of variance for nine characters viz., days to 50% flowering, days to maturity, plant height, number of branches per plant, pod bearing length, number of pods per plant, number of seeds per pod, seed yield per plant and hundred seed weight. Molecular diversity using 18 polymorphic simple sequence repeat (SSR) markers divided genotypes into 15 clusters, of which ICP11059 and AK-101 were solitary, indicating their distinctiveness among all genotypes. Similarly, BSMR-533, JKM-7, RVK-285, ICP-1126, ICP-348, ICP-6859 and ICP-7869 were found distinct among the genotypes. Geographical origin based diversity separated Indian and non Indian genotypes. The Un weighted Pair Group Method with Arithmetic mean (UPGMA) based dendrogram indicated distinctiveness of ICP-13633 and Bennur local, as they formed solitary cluster. The SSR marker CcM 602, as it could differentiate 4 genotypes at different base pair size can be used for identification and finger printing of genotypes

Integrated nutrient management for improving crop yields, soil properties, and reducing greenhouse gas emissions

Recently, most agrarian countries have witnessed either declining or stagnant crop yields. Inadequate soil organic matter (SOM) due to the poor physical, chemical, and biological properties of the soil leads to an overall decline in the productivity of farmlands. Therefore, the adoption of integrated nutrient management (INM) practices is vital to revive sustainable soil health without compromising yield potential. Integrated nutrient management is a modified nutrient management technique with multifarious benefits, wherein a combination of all possible sources of plant nutrients is used in a crop nutrition package. Several studies conducted in various parts of the world have demonstrated the benefits of INM in terms of steep gain in soil health and crop yields and at the same time, reducing greenhouse gas emissions and other related problems. The INM practice in the cropped fields showed a 1,355% reduction in methane over conventional nutrient management. The increase in crop yields due to the adoption of INM over conventional nutrient management was as high as 1.3% to 66.5% across the major cropping systems. Owing to the integration of organic manure and residue retention in INM, there is a possibility of significant improvement in soil aggregates and microbiota. Furthermore, most studies conducted to determine the impact of INM on soil health indicated a significant increase in overall soil health, with lower bulk density, higher porosity, and water-holding capacity. Overall, practicing INM would enhance soil health and crop productivity, in addition to decreasing environmental pollution, greenhouse gas emissions, and production costs

Development and Commercialization of CMS Pigeonpea Hybrids

The role of heterosis in enhancing productivity in food crops is well known. Legume breeders have not been able, however, to take advantage of this genetic phenomenon for a long time, due to biological restrictions, such as the requirement of high seeding rate and the inability to produce large quantities of F1 hybrid seed. Recently, in pigeonpea (Cajanus cajan (L.) Millsp.), a breakthrough has been realized with the development and marketing of the world’s first legume hybrid, ICPH 2671. The key for this achievement was breeding and using a stable cytoplasmic nuclear male sterility (CMS) system obtained from the cross between C. cajanifolius, a wild relative of pigeonpea, and the cultivated type. The inherent partial natural out‐crossing of pigeonpea was knitted with this CMS system to facilitate economically‐viable large‐scale hybrid seed production. These developments provided opportunities to overcome the historic stagnant low yield (0.6–0.8 t ha–1) through heterosis breeding. Among hundreds of hybrid combinations tested, a cross between ICPA 2043 and ICPL 87119 (=ICPR 2671), designated as ICPH 2671, was the most promising, with >40% yield superiority (reaching yields above 3 t ha–1) over the prevalent cultivar ‘Maruti’, in multi‐location, multi‐year, on‐station trials, as well as on‐farm evaluations. The outstanding performance of ICPH 2671 led to its release in 2010 as the first medium duration commercial pigeonpea hybrid in India. Subsequently, two additional pigeonpea hybrids, ICPH 3762 and ICPH 2740 were also released for commercial cultivation in India in 2014 and 2015, respectively. According to recent estimates, in 2015 the CMS‐based pigeonpea hybrids were grown over 150,000 hectares in central and southern India. In this review, we summarize the research efforts that led to the milestone of developing the first commercial hybrid in food legumes

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Not AvailableAn experiment was conducted to determine the nature and magnitude of heterosis in castor for seed yield and its yield attributing traits. Forty hybrids were synthesized involving five lines and eight testers through line x tester (L×T) mating design and were evaluated for yield and its components. Among 13 parental lines, JP-96, VP-1, DPC-9, RG-2661-1, RG-109 and RG-3160 were identified as good general combiners for seed yield and its components, which can be directly exploited in heterosis breeding. The cross combination, DPC-18 × RG-2661-1 was good specific combiner for early maturity. High seed yield per plant was recorded for hybrids: VP-1×RG-109 (105.04 g), DPC-18×RG-1771 (98.26g) and DPC-18×RG-2661-1 (97.97 g). These promising crosses involved parents with high × high and high × low GCA effects and were found promising for high yield potential in castor.Not Availabl