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ThesisItem Open Access Generation mean analysis studies in okra (abelmoschus esculentus L. moench)(Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, 2019-08-21) Zate, Dilip Kondbarao; Jawale, L.N.The present investigation, entitled “Generation mean analysis studies in Okra (Abelmoschus esculentus (L.) Moench)” was undertaken using six generations viz., P1, P2, F1, F2, B1 and B2 derived from four crosses namely ( Parbhani Kranti × VROR-159, Parbhani Kranti × Kashi Pragati , Kashi Satadhari × VROR-159 and Kashi Satadhari × BO-2) and it was carried out to estimate the gene effect, heterosis, inbreeding depression, heritability and genetic advance. The material along with check Pusa Sawani and Mahyco Bhindi No -10 were evaluated in a Randomized Block Design with three replicates during kharif, 2017. The characters studied were Plant height (cm), Internodal length (cm), Number of nodes on main stem, Number of branches per plant, Days to first flowering. Days to 50% flowering, First fruiting node. Fruit length (cm), Fruit diameter (cm), Fruit weight (g), Number of ridges per fruit, Number of fruits per plant, Marketable fruit yield per plant (g) Yield per plot (Kg), fruit yield (q/ha.), Incidence of Fruit and shoot borer (%) and Incidence of Yellow vein mosaic (%). Analysis of variance for yield and yield components showed highly significant differences among the crosses studied for all the character except for days to flowering in a cross Kashi Satadhari × VROR-159 and Kashi Satadhari × BO-2 and 50% flowering in Kashi Satadhari × BO-2 which indicated the presence of substantial variability in the material under study. Inadequacy of additive-dominance model was evident by the significance of one or more scaling tests A, B, C and D as given by Mather (1949) indicating presence of non-allelic gene action in most of the crosses for various characters under studied. Joint scaling test was significant for all traits except for number of ridges per fruit. The individual scaling tests indicated that the simple additive dominance model was unable to explain the total genetic variability in all the crosses and presence of epistasis was observed for all the seventeen characters studied estimation of main as well as digenic interaction effects by six parameter models revealed the significance of both main and digenic interaction component for various characters. However magnitude of dominant and epistasis components was greater than additive components in most of the characters. The magnitude of dominance (h) component was higher than additive component in characters indicating its predominant occurrence in the inheritance of these characters. The prevalence of duplicate type of epistasis in all the characters over one or more crosses except number of nodes on main stem showing complementary epistasis further confirms the prevalence of dominance gene action. Among the digenic gene component, the dominance × dominance (l) component in general had enhancing effect in the expression of the characters. The additive × additive (d) gene effect was also evident in most of the characters. In heterosis and inbreeding study of F1 and F2 generation, relative heterosis ranges from -46.29% for first fruiting nodes to 44.41% for number of nodes on main stem. The highest relative heterosis for fruit yield per plant in F1 hybrid cross Kashi Satadhari × BO-2 (18.83%) followed by Parbhani Kranti × VROR-159 (15.81%) were recorded over mid parent. However, highest heterobeltiosis in Kashi Satadhari × BO-2 (15.00%) and Parbhani Kranti × VROR-159 (11.68%) and highest standard heterosis observed in Parbhani Kranti × VROR-159 over Pusa Sawani (24.04%) and Mahyco Bhindi No.(19.31%). However, highest positive relative heterosis recorded in Kashi Satadhari × BO-2 (44.41%) for first fruiting nodes and negative relative heterosis observed in Kashi Satadhari × VROR-159 (-46.29%). Inbreeding depression ranges from -106.89% for first fruiting nodes in cross Kashi Satadhari × VROR-159 to 25.81% for internodal length in cross kashi Satadhari × BO-2. However, Inbreeding depression for marketable fruit yield per plant (g) was highest observed in Parbhani Kranti × Kashi Pragati (12.45%) followed by Parbhani Kranti × VROR-159 (12.07%). Among the four crosses, Parbhani Kranti × VROR-159 showing superior over standard check Pusa Sawani for traits. viz. plant height, Fruit weight, Number of fruit per plant, Marketable fruit yield per plant, Fruit yield per plot and Fruit yield per hectare, Number of branches per plant, Number of nodes on main stem, Fruit length and Incidence of yellow vein mosaic (%), days to first flowering and days to 50% flowering and over check Mahyco Bhindi No.10 for traits viz. plant height, Fruit weight, Number of fruit per plant, Marketable fruit yield per plant, Fruit yield per plot and Fruit yield per hectare, Number of nodes on main stem. Crosses which showing significant and positive heterosis for marketable yield per plant also exhibited significant and positive heterosis for its component traits like number of fruits per plant, fruit length, fruit diameter, plant height, number of branches per plant, which indicated that heterotic effect for marketable yield per plant was mainly due to manifestation of heterosis in yield components Broad sense heritability ranges from 31.11% for fruit diameter (cm) in cross Kashi Satadhari × VROR-159 to 97.90% for plant height in a cross Parbhani Kranti × VROR-159. However, highest broad heritability observed in kashi Satadhari × BO-2(89.30) followed by Parbhani Kranti × VROR-159 (78.60%) and narrow sense heritability in Kashi Satadhari × BO-2 (62.25) followed by Parbhani Kranti × VROR-159 (46.56%). However, highest broad sense heritability was observed in Kashi Satadhari × BO-2(97.90%) for number of nodes on main stem and Kashi Satadhari × VROR-159 (97.90%) for number of ridges per fruit. Highest Narrow sense heritability recorded in cross Parbhani Kranti × VROR-159 (83.90) for plant height. Genetic advance at 5% ranges from 0.06% in a cross Kashi Satadhari × VROR-159 for fruit diameter to 44.09% in a cross Parbhani Kranti × VROR-159 for plant height. Genetic advance over mean (%) at 5% ranges from 3.08% in a cross kashi Satadhari × BO-2 to 64.59% in a cross Kashi Satadhari × VROR-159 for incidence of yellow vein mosaic (%). High broad sense heritability was observed for yield and its components. Moderate narrow sense heritability coupled with low to moderate genetic advance as per cent of mean was observed for Number of fruits per plant, marketable fruit yield per plant yield per plot, yield per hectare. These characters showed non additive gene action and hence improvement through heterosis breeding or recurrent selection would be effective.