Farmers’ participatory varietal selection in groundnut: a case study from Tamil Nadu, India

Seven Virginia bunch groundnut genotypes viz., VG 9902, ICGV 86325, ICGV 96217, ICGV 97115, ICGV 87846, ICGV 98369 and ICGV 98370 were evaluated in nine villages as mother and baby trials with local check. A detailed score chart was provided to farmers for ranking the genotypes. ICGV 87846 was significantly superior to all other genotypes for all the traits. A little early and synchronous flowering habit of ICGV 87846 may be the reason to escape the early drought. The produce of all the genotypes were exposed to the local groundnut traders for evaluation. ICGV 87846 the was most preferred by them due to its superior pod and kernel traits. The basic seeds of the farmers’ and traders’ preferred genotype ICGV 87846 were provided to the farmers to motivate the informal seed production systems. Hence it is evident that in the participatory breeding, new genotypes reach the release phase much faster than in conventional breeding and are better suited to farmers need

Identification of quantitative trait loci (QTL) for late leaf spot disease resistance in groundnut (Arachis hypogaea L.)

TMV 2, a LLS susceptible genotype and the COG 0437, a LLS resistant genotype were crossed and their F2 population was used for marker analysis in the present investigation. The phenotypic mean data on F2: 3 progenies were used as phenotype. Seventy seven SSR markers were used for the parental polymorphism. Among SSR markers, nine markers were found polymorphic between the parents TMV 2 and COG 0437. Eight markers formed a linkage group and covered a distance of 37.2 cM with an average 4.65 cM at LOD 3.0. The composite interval mapping analysis resulted in two QTLs viz., each one for hundred kernel weight and LLS severity score with 6.1 and 37.9 R2 respectively. The nearest marker for QTLs of hundred kernel weight and LLS severity score were Ah 4–26 and PM 384 respectively. The markers PMc 588 (3.9 cM) and Ah 4–26 (4.3cM) are the flanking markers for PM 384 and hence these flanking markers can be used for marker assisted breeding for LLS resistance. The parent COG 0437 is the major contributor for both of these QTLs. Considering the phenotypic variation explained by these QTLs, identification of more effective QTLs for hundred kernel weight is required to utilise in the marker assisted breeding programme. However the LLS QTL has 37.9 per cent of phenotypic variation explained and hence can be effectively utilised in marker assisted breeding programme. By using these QTLs, plant breeders can effectively monitor the flow of inheritance of the resistance characters along with desirable phenotypic traits

SSR markers associated for late leaf spot disease resistance by bulked segregant analysis in groundnut (Arachis hypogaea L.)

Late leaf spot (LLS) caused by Phaeoisariopsis personata is the major foliar disease that reduces the pod yield and severely affects the fodder and seed quality in groundnut. Molecular markers linked with LLS can improve the process of identification of resistant genotypes. In the present study, a LLS susceptible genotype (TMV 2) and the LLS resistant genotype (COG 0437) were crossed and their F2 population was used for marker analysis. The phenotypic mean data on F2:3 progenies were used as phenotype. Parents were surveyed with 77 SSR (Simple Sequence Repeat) primers to identify polymorphic markers. Among SSR markers, nine primers were found polymorphic between the parents TMV 2 and COG 0437. These markers were utilized for bulked segregant analysis (BSA). Among the polymorphic SSR markers, three primers viz., PM 375162, pPGPseq5D5220 and PM 384100 were able to distinguish the resistant and susceptible bulks and individuals for LLS. In single marker analysis, the markers PM 375, PM 384, pPGPseq5D5, PM 137, PM 3, PMc 588 and Ah 4-26 were linked with LLS severity score. The phenotypic variation explained by these markers ranged from 32 to 59 %. The markers identified through BSA were also confirmed with single marker analysis. While validating the three primers over a set of resistant and susceptible genotypes, the primer PM 384100 allele had association with resistance. Hence PM 384 could be utilized in the marker assisted breeding programme over a wide range of genetic background

A new high yielding Spanish bunch groundnut variety CO 7 (ICGV 00351) for the drought prone areas of Tamil Nadu

A high yielding Spanish bunch groundnut culture ICGV 00351 (a cross derivative of ICGV 87290 X ICGV 87846) developed at ICRISAT (International Crops Research Institute for the Semi-Arid Tropics), Patancheru, Andhra Pradesh was evaluated along with six other promising varieties in drought prone areas of Tamil Nadu under Farmers’ Participatory Varietal Selection Trials. Culture ICGV 00351 recorded an overall mean dry pod yield of 2189 kg/ha under rainfed situation. This culture with duration of 105 to 110 days registered a pod yield increase of 17 and 26 per cent over the popular varieties of this region viz., VRI (Gn) 6 and TMV (Gn) 13 respectively. It has 71% shelling and 51 % oil and 22% protein content. This culture has also showed tolerance reaction to major foliar diseases viz., late leaf spot and rust. As this variety has improved pod yield along with consumer and trader preference, this culture ICGV 00351 has been released as CO 7 for cultivation in the entire state of Tamil Nadu

Stability analysis of foliar disease resistant groundnut genotypes (Arachis hypogaea L.)

Fifteen foliar disease resistant groundnut genotypes and one local variety (VRI 4) were evaluated over four seasons in asingle location to identify the stable high yielding genotypes. Significant G X E interaction showed the differentialperformance of genotypes over different environments / seasons. Stability analysis revealed that only one genotype(ICGV 92093) had near unity regression coefficient coupled with non-significant deviation from regression and highmean kernel yield. Hence, the genotype may be recommended over wide range of environments / seasons

Genetic divergence of inbred lines in sunflower (Helianthus annuus L.)

Genetic divergence of 79 inbred lines of sunflower using eight agronomic characters was studied. Analysis of variance revealedthe existence of divergence among the inbred lines. Mahalanobis D2 statistics indicated the presence of substantial geneticdiversity. Based on intercluster D2 value and cluster mean for various characters, potential inbred lines were identified.Intercrossing of these inbreds will exhibit more variability for yield and yield component traits. The character oil yield was foundto be important as the major contributor for genetic divergence. The usefulness of genetic divergence for the identification ofparents for heterosis breeding is not proved and needs further research