Browsing by Author "Suma Bai, D I"

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Gamma ray induced variation for yield in sweet potato
(Kerala Agricultural University, 1995) Suma Bai, D I; Nayar, N K
Genetic analysis of yield and its components in fodder maize
(Kerala Agricultural University, 1995) Sreekumar, S G; Suma Bai, D I
Nine fodder maize types were evaluated in a randomized block design with three replications during summer 1992 at the College of Agriculture, Vellayani under the AICRP (Forage Crops). Genetic analysis of fodder yield and its components revealed that plant height and plant population recorded high genotypic coefficient of variation, heritability and genetic advance indicating that selection based on these characters will result in improving fodder yield. Highest genotypic correlation was observed between green and dry fodder yield and also between plant population and dry fodder yield. High heritability and high genetic advance observed for plant height indicate additive gene action and the reliability of this character during selection programmes for improving the yield.
Genetic analysis of yield and its components in fodder teosinte (Euchlaena mexicana L. Schrad)
(Kerala Agricultural University, 2000) Suma Bai, D I; Lekha Rani, C
Ten fodder tcosintc types were evaluated in a randomized block design with three replications during Kharif 1995 at the College of Agriculture, Vellayani under AICRP on Forage Crops. Genetic analysis of fodder yield and its components revealed that plant height recorded high genotypic coefficient oi' variation, herilability and genetic advance indicating that selection based on this character will result in improving fodder yield. Highest genotypic correlation was observed between green fodder yield and dry matter yield. Leaf number per plant and plant stand recorded highest positive genotypic correlation with green fodder yield.
Genetic analysis of yield and quality attributes in fodder cowpea (Vigna unguiculata (L.) Walp)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Radhika, V S; Suma Bai, D I
Genic manipulations in sweet potato adopting induced mutations
(Department of Agricultural Botany, College of Agriculture,Vellayani, 1989) Suma Bai, D I; Krishnan Nair, N
An experiment was conducted at the Department of Agricultural Botany, College of Agriculture, Vellayani during 1987-1989 for genetic manipulations in sweet potato through gamma ray induced mutagenesis for increased variability and to isolate out genotypes having wider adaptability and better performance. Stem cuttings of 8 to 10 cm length bearing two nodes each, taken from fifteen sweet potato varieties were used for radiosensitivity analysis. Gamma irradiation was done by a 60 Co gamma cell unit installed in the Radio Tracer Laboratory of Kerala Agricultural University, Trichur. The material was subjected to exposure of 2-10 kR at intervals of 2 kR. The chosen dose rate was 0.162 MR/h. The direct effect of doses on the material was assessed on the basis of days to start sprouting, days to complete sprouting, sprouting percentage, vine length, branch and tuber number and weight of tubers per vine. The exposures above 4 kR caused lethality in the majority of the varieties and hence comparative analysis for ratiosensitivity was assessed at the 2 kR level. The gamma ray exposed population started sprouting late. The days taken for completion of sprouting were also more in all the varieties. Gamma rays, in addition, reduced the sprouting percentage. The percentage lethality varied depending on variety. The vine length and number of branches per vine also varied from variety to variety. They were found to be comparatively less in treated population. The tuber number and weight of tubers per vine were found to be significantly increased by gamma irradiation at 2 kR. Based on the above observations the fifteen varieties were classified into three, viz. low, medium and high radiation sensitive categories. Induced mutagenesis was done in continuation with the radiosensitivity analysis using three varieties, each selected from the low, medium and high radiation tolerant groups. The planting materials selected for gamma irradiation included fresh cuttings, rooted cuttings and rooted tubers which were exposed to radiation at a range of 500 – 2500 r, at 500 r intervals. The dose rate was 0.162 MR/h. The irradiated materials along with the control were planted on the subsequent day. In vM1 generation the direct effect of gamma rays was assessed based on days taken to start sprouting, days taken to complete sprouting, sprouting percentage, lethality on the 30th day of planting and at harvest, vine length, branch number per vine, fresh weight of vine, tuber number per vine, weight, length, girth and volume of tuber and tuber yield per vine. From vM1 plants 3-4 noded cuttings were taken from the basal, middle and top portions for raising vM2 generation. VM3 and vM4 generations were also raised in the same manner. In vM2, vM3 and vM4 generations the yield parameters were analysed in detail. Classification of the phenotypes and frequency analysis were also done. The salient findings of the experiment are the following: There was a delay in sprount initiation and for completion of sprouting caused by gamma ray exposure. A decrease in sprouting percentage and an increase in lethality were noticed under higher levels of exposures. Similarly a reduction in vine length and branch number per vine were found at higher exposures. The fresh weight of vine was reduced and the tuber number increased at higher exposures. There was an increase in mean tuber weight, length, girth, volume and tuber yield per vine at higher exposures. All the exposures and the different modes of treatment induced phenotypic variants both in negative and positive directions. Positive variants were in higher frequency in later generations. Irradiation of rooted cuttings was found to be more economical or beneficial compared to fresh cuttings and rooted tubers. The study enabled to isolate out two promising types, one each from S5 and Bhadrakalichuvala. These mutants outyielded the control and are being multiplied by vine cuttings for farm trials in different agroecological milieus of the State.
Heterosis and gene action in bajra - napier hybrids
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2002) Serene Das, M; Suma Bai, D I
A study on 'Heterosis and gene action in bajra-napier hybrids' was carried out with the objective of developing bajra-napier hybrids with high yield potential and good quality. The study was undertaken during the year 2001-2002 in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Seven lines of bajra, viz., APFB-2, Composite 9, DRSB-3, FD 1917, HES-4, IP 15814 and TNSC-4 and three testers of napier grass, FD 431, FD 467 and FD 471 were crossed in a line x tester mating design to obtain 21 cross combinations. The hybrids were evaluated along with their parents for mean performance, combining ability, heterosis and gene action for eleven yield and yield related characters. Significant differences among treatments were observed for all the characters. Also significant differences among parents and crosses were observed for these characters and their general and specific combining ability variances and effects were studied. The magnitude of SCA variances alone was significant suggesting the predominance of non-additive gene action in controlling these traits. Based on mean performance and gea effects, HES-4 was identified as the best general combiner among lines followed by TNSC-4. Among testers, FD 467 can be selected as the best male parent followed by FD 471. The crosses, TNSC-4 x FD 471 and HES-4 x FD 467 were the promising combinations for green fodder yield and its component traits, based on mean performance, sea effects and standard heterosis. Hence these crosses can be exploited for developing high yielding hybrids.
Interspecific Hybridisation in Sorghum
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2005) Jithesh, V G; Suma Bai, D I
A study on ‘Interspecific hybridization in Sorghum’ was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2003-2004 with the objective of developing sorghum-sudan grass hybrids with high fodder yield potential and better quality. Five superior accessions of sorghum viz., GD 65174-1,GD65174-2, GD 65195, GD 65239 and Acc. No. 846 (lines) with high yield potential and better palatability and three accessions of sudan grass viz., Jhansi local, SSG-59-3 and IS-720 (testers) with high tillering ability were crossed in a Line x Tester mating design to obtain 15 hybrid combinations. The lines, testers and their hybrids were evaluated along with a check COFS-29 in a replicated field trial for mean performance, combining ability and heterosis. Observations on plant height, tiller number per plant, stem girth, internodal length, leaf/stem ratio, leaf number per plant, leaf weight per plant, days to 50 per cent flowering, green fodder yield, dry fodder yield, crude protein content, crude fibre content and HCN content were recorded. Significant differences among treatments were observed for all characters. Significant differences among crosses were observed for all characters except tiller number per plant. General and specific combining ability variances and effects were studied. The magnitude of SCA variance alone was significant suggesting the predominance of dominance gene action in controlling these traits. Based on mean performance and gca effects, Acc. No. 846 was identified as the best general combiner among lines and SSG-59-3 among testers. The crosses, GD 65195 x IS-720 and Acc. No. 846 x SSG-59-3 were found to be promising for green fodder yield and its component traits based on mean performance, sca effects and standard heterosis. Hence these crosses can be advanced for further trials for developing superior sorghum-sudan grass hybrid varieties.
Quantitative variation and genetic divergence in fodder rice bean [Vigna umbellata (Thunb.) Ohwi and Ohashi]
(Department of Plant Breeding and Genetics, College of Agriculture,Vellayani, 2002) Salu Appan, B; Suma Bai, D I
Seedling progeny analysis in selected clones of guinea grass [Panicum maximum Jacq.]
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1997) Babu, R; Suma Bai, D I
Sneha, an improved variety of groundnut for uplands
(Kerala Agricultural University, 2000) Suma Bai, D I; Manju, P; Sverup John; Wilson, D; Gopimony, R; Vijayagopal, P D
Initial evaluation trials (lETs) were conducted with 18 superior types and 18 extra early segregants from the Fs progenies during 1993. From the lETs, seven high yielding types and nine high yielding, extra early progeny bulks were selected and subjected to CYTs during kharif 1994 and 1995 at the College of Agriculture, Vellayani, Thiruvananthapuram along with check varieties. Two promising types, VGE-551 and 1SKO-8805 with high yield and two cultures, Culture 15 and Culture 18 with high yield and early maturity were advanced to farm trials along with TMV 2 and local check at nine locations in Thiruvananthapuram district during kharif 1996. Culture 15 with high yield and early maturity was recommended for release as Sneha suitable for cultivation in the uplands of Thiruvananthapuram district.
Variability studies in fodder sorghum (Sorghum bicolor (L.) Moench)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Bini K; Suma Bai, D I
A research programme was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during August to November 2002 with the objective of estimating the variability in important economic characters and to select superior accessions of fodder sorghum .The experiment was conducted using 50 accessions of fodder sorghum collected from ICRISAT adopting a randomized block design with two replications. Data collected on eleven characters were subjected to statistical analysis. Coefficients of variation, heritability, genetic advance, correlation among the characters, path analysis and selection index were estimated. Analysis of variance revealed significant difference among the accessions for all the characters. Phenotypic and genotypic coefficients of variation were high for leaf weight per plant, green fodder yield, number of leaves per plant, leaf area index and number of tillers per plant. High heritability coupled with high genetic advance for plant height at harvest, leaf weight per plant and green fodder yield revealed the presence of additive gene action. Hence simple pedigree method will be effective for improvement of these traits. Correlation studies indicated that crude protein content, leaf weight per plant, plant stand after germination, leaf area index and plant height at harvest exhibited significant positive correlation with green fodder yield. Leaf weight per plant exhibited the highest positive direct effect on green fodder yield followed by leaf area index and plant height at harvest. Based on selection index with respect to eleven characters studied, ten superior accessions were selected by exercising 20 per cent selection. They were Acc. Nos.11079, 11026, 11446, 680, 11456, 670, 11128, 11298, 1005 and 902.
Yield potential and adaptability of black gram genotypes for rice fallows
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Saji Kumar, K R; Suma Bai, D I
A research programme was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during January-April 1995 with the objective of assessing yield potential and adaptability of black gram genotypes in summer rice fallows. Thirty varieties were evaluated adopting a randomised complete block design with three replications. Data on twenty one characters were collected and subjected to statistical analysis. Analysis of variance revealed significant difference among the varieties for all the characters except number of pickings. Genotypic and phenotypic coefficients of variation were highest for incidence of rust disease, leaf area index, biological yield, seed yield per plant and height of plant. High heritability coupled with high genetic advance was recorded for leaf area index, height of plant, number of pods per plant and stomatal distribution suggesting the reliability of these characters during selection progrmme. High positive genotypic correlation of pod weight, number of pods per plant and number of pod clusters per plant with grain yield has indicated that selection based on the above components result in the improvement of grain yield. Selection index based on yield contributing characters has enabled to select six high yielding adaptable black gram genotypes viz. Co-Bg-309, Co-Bg-9, B-3-8-8-1, WBG-67, Co-Bg-303 and T-9.