Thirty two F6 progenies with along with 4 released varieties as parents were evaluated in R.B.D for yield and its component traits grown in rabi
season showed a wide range of variation in all the 10 morphometric traits including yield. The genotypic source of variations were highly significant (at 1% level) for all the traits. The P.C.V. and G.C.V. estimates were high for haulm yield per plant and low for harvest index and shelling percent. The rest of the characters exhibited medium PCV and GCV. However, low values of G.C.V. were observed in shelling percentage and harvest index indicated the need to create variability either by hybridization or mutation followed by selection. High heritability and high genetic advance indicated that these traits are mainly governed by additive gene action and responsive to selection. Hence improvement of these traits would be more effective through the phenotypic selection. Thus harvest index and shelling percent were controlled largely by non-additive gene action and selection would be less effective. Moderate heritability and genetic advance (GAM) as percent of mean for plant height, pod number per plant, kernel number per plant, kernel yield and pod yield indicated the additive and non-additive gene actions for these traits and phenotypic selection would be effective to some extent. Kernel yield per plant had the highest direct positive effects on pod yield per plant followed by number of kernels per plant and 100 kernel weight. All other characters through these three characters made major indirect contribution towards pod yield. Plant height, number of branches per plant and number of pods per plant exhibited greater influence on pod yield per plant via kernel number per plant and kernel yield per plant. Haulm yield and harvest index influenced indirectly on pod yield through kernel weight and kernel number respectively. Present study thus indicated that for selection major emphasis should be laid on kernel yield per plant, number of kernels per plant, hundred kernel weight followed by plant height and number of branches per plant. Thus, kernel yield per plant, number of kernels per plant, hundred kernel weight followed by plant height and number of branches per plant were identified as the most important yield components and due emphasis should be placed on these characters while selecting for high yielding genotypes in Spanish bunch groundnut.
In the present study D2 analysis was done. The advance breeding lines showed considerable amount of diversity for the morphological traits. On the basis of average D2, haulm yield per plant contributed maximum divergence followed by pod yield per plant, kernel yield and kernel number per plant. Shelling percent contributed least divergence. All other characters like plant height, number of branches per plant, harvest index, pod number per plant and hundred kernel weights contributed less to D2 estimates.
On the basis of critical D2 value (60), 36 genotypes were classified into 10 clusters. Four parents of Spanish groundnut released varieties and their 32 cross derivatives in F6 generation were grouped into ten different clusters. This indicated the large diversity existing in the groundnut varieties giving the opportunity for further improvement in groundnut. Thus recent released varieties contain sufficient diversity. Cluster X, IX and III accommodated ten, eight and four genotypes respectively. Rest of the clusters contains two genotypes each. Cluster X was the largest, accommodating as many as 10 genotypes. The progenies of AK 12-24 X TG 26 were grouped into one cluster i.e., cluster X, different from their parent present in cluster III. The progeny OG Y19 remained with its parent R2001-3 indicating its similarity with parent. Similarly OG Y5 and OG Y7 remained with one of their parent TG 26 while OG Z1 and OG Z2 clustered with one of their parent AK 159. Except these genotypes, other progenies remained in different clusters away from their parent. Thus hybridization among the released varieties in groundnut created genetic diversity due to recombination of characters. The clustering pattern of genotypes showed that the genotypes of different origins/parent were clubbed into one cluster whereas the genotypes belonging to same parent or origin were grouped into different clusters indicating that the new genetic recombination increased genetic diversity giving rise to transgressive segregants. Small intra cluster D2 value of cluster I, II, IV, V, VI, VII and VIII indicated genotypes within a cluster resemble very close to each other. The genotypes of each cluster belong to same parental origin. Large intra cluster D2 value of cluster III, IX and X indicated their less divergence. These three clusters also exhibited large inter cluster distance with rest of the clusters. Maximum inter cluster distance was observed between cluster III and cluster X followed by cluster III and cluster IX. Inter cluster distance is the main criterion for selection of genotypes. In this context the genotypes from cluster III, IX and X could be selected as parents for hybridization. Cluster IX showed lowest number of branches per plant, harvest index, number of pods per plant, kernel number per plant and pod yield per plant while cluster X exhibited highest value for haulm yield per plant and hundred kernel yield per plant. Thus OG Z5 may be selected as best parent for cross with AK 12-24 exhibiting high mean value for yield and yield contributing characters for obtaining better recombinants or may be advanced for use as new improved breeding line.
But OG Z 5 recorded highest pod and kernel yield per plant with haulm yield although exhibited moderate chlorophyll and protein values. Chlorophyll, protein and yield were not related in the same magnitude and direction in all the crosses. The highest yield obtained in OG Z5 with moderate chlorophyll content is due to the balance in the physiological parameters contributing towards yield. Total chlorophyll are positively correlated with kenel yield and negatively with biological yield and vice versa.
Majority of band ranges from 43.0 KDa to 14.3 KDa. Number of band ranges from 11 to 19. 11 numbers of polymorphic bands are observed. Highest numbers of polymorphic bands are observed in AK 12-24, OG X1, OG X2, OG X3, OG Z2 and OG Z3.
Comparing the composition of the clusters obtained using D2 values based on yield and yield contributing characters and dendrogram, based on protein banding pattern; it was observed that the divergent progeny OG X4 in family AK 12-24 X TG 26 remained in cluster IX different from both the parent. Similarly the progenies like OG Y6, OG Y 7, OG Y 8, OG Y 18, OG Y20,OG Y 9, OG Y16, OG Y 10, OG Y 11,OG Y 13, OG Y 12 OG Y 15 and OG Y14 remained in different clusters other than the parent of cross R 2001-3 X TG 26. In family AK 159 X TG 26, the progenies like OG Z4 and OG Z1 remained in cluster IX with parent AK 159 but different from parent TG 26. Thus OG Z1 and OG Z4 exhibiting divergence at protein level are expressing differently at morphological level due interaction of morphological traits with environment. Morphological traits expressed through interaction of environments, put the genotypes of family R 2001-3 X TG 26 into different clusters, obtained based on protein banding.
OG Z5 & OG Z6 may be identified as promising line for high protein content (25%) and (31%) with moderate chlorophyll and higher yield. OG X4 which is a high yielder and diversified line shown by protein banding may identified as a better line.
Out of 36 genotypes evaluated the genotypes like OG Z5, OG Z2, R 2001-3A, OG Z6 and OG X4 were sorted out to be promising in respect of high yield. The higher productivity in these promising lines is due to a combination of various morpho- physiological traits and which could be ascribed as the basis of potential productivity in groundnut. High yield of different promising entries could be attributed to taller plant height, moderate to high number of branches /plant and number of pods per plant and moderately high 100 kernel weight, may serve as the basis of yield vigour which could be utilized as important selection criteria for prediction and realization of high yield in groundnut.