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19902
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Subject: Agriculture × Author: KAU × End date: 1999 × Start date: 1990 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Induced mutations in banana var. Nendran
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1990) Radha Devi, D S; KAU; Krishnan Nair, N
    The present investigations was carried out in the Department of Agricultural Botany, College of Agriculture, Vellayani during 1985-88 and in the plant tissue culture Laboratory attached to the Department of Plantation Crops, College of Horticulture, Vellanikkara, Thrissur during 1986-88. The project was taken up to standardise the techniques for induced mutagenesis in-vitro and in-vitro in banana (Musa paradiciaca L.) var. nendran and aslo to analyse the direct effect of 60 Co gamma rays on growth and bunch characters in the vM1 and vM3 generations. One, two and three months old suckers of various sizes (after removal of 25 to 75 per cent of the pseudostem) were exposed to 1.0, 1.5, 2.0, 2.5 and 3.0 kR gamma rays. For in-vitro mutagenesis, isolated shoot tips were exposed to 0.50, 0.75, 1.00, 1.25 and 1.50 kR gamma rays. Ex-vitro analysis of five plants per treatment per exposure was done in the vM1 generation for various growth, bunch and fruit characters.
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    ThesisItemOpen Access
    Genetic analysis in red gram (Cajanus cajan L.)
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1990) Achamma Oommen; KAU; Narayanan Namboodiri, K M
    The research project "Genetic analysis in red gram" was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Trichur during the period 1985-90. A 5 x 5 diallel cross, excluding reciprocals conducted in red gram revealed the predominance of additive gene effect for all the characters except days to first flowering. The combining ability analysis showed PLA-550 as the best general combiner; and the F 1 of the cross UPAS-120 x I.C. 15708 to have good specific combining ability. Negative heterosis over both the parents was exhibited by UPAS-120 x I.C. 15708 and PLA-550 x PLA-600 for days to first flowering and days to maturity which showed that early maturing segregants could be obtained from these crosses. The same crosses showed relative heterosis for yield also. The analysis of generation means by using six parameter model revealed the importance of both additive and dominance gene effects in the expression of most of the characters. Additive x additive and dominance x dominance effects showed influence in the expression of the characters. Among the components of variances dominance variance was higher for most of the characters. Heritability in narrow sense was found to be low. Number of clusters per plant and number of pods per plant were highly correlated with yield in parents, F 1 's and F2's. As the yield and yield components in the present study were under all the three types of gene action viz., additive, dominance and epistasis, reciprocal recurrent selection procedure seems to be the best suited method of breeding for improvement of this crop.