1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
Permanent URI for this communityhttp://localhost:4000/handle/123456789/1
Browse
2 results
Search Results
Item Generation mean analysis in yard long bean (Vigna unguiculata subsp.sesquipedalis (L.) Verdcourt) for yield and mosaic resistance(Vegetable Science, College of Agriculture, Vellayani, 2024-02-13) Airina, C K.; KAU; Sarada, SThe present study ‘Generation mean analysis in yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) for yield and mosaic resistance ' was undertaken at the department of Vegetable Science, College of Agriculture, Vellayani, Thiruvananthapuram during 2017-2019 and at Pepper Research Station, Panniyur, Kannur during 2022-23 to develop high yielding and mosaic resistant yard long bean hybrids and to study the inheritance and gene action of yield and mosaic resistance using generation mean analysis. Seventy six cowpea genotypes were screened against the blackeye cowpea mosaic virus (BlCMV) to ascertain the disease reaction of the genotypes by artificial inoculation under pot culture method. Based on the extent of symptoms and vulnerability index (VI), three genotypes were found highly resistant, 11 genotypes showed resistant response, 13 genotypes were moderately resistant, 10 genotypes moderately susceptible, 20 genotypes susceptible and remaining 18 genotypes showed a highly susceptible reaction. The genotypes Manjari, VU-7 and EC-18734 were highly resistant to BlCMV. Five high yielding yard long bean genotypes viz; Vellayani Jyothika, Vyjayanthi, Geethika, KAU Deepika, and KAU Mithra which gave a susceptible response were selected as lines and three genotypes, viz. Manjari, VU-7 and EC-18734, which gave an immune response as testers for the development of 15 hybrids in a line x tester fashion. The hybrids and their eight parents were raised with a standard variety Lola and resistant check Manjari in a randomized block design with three replications in open field in Rabi 2022 and were tested for 19 yield characters and mosaic resistance. The mean squares due to parents were highly significant for all the characters, while for hybrids significant difference was observed for all the characters except pod girth and yield per plot. The PCV values for all the characters were found to be higher than the GCV values but in smaller magnitude, which implied a lesser influence of environmental factors for these characters. The PCV and GCV values ranged from 3.31 to 52.80 and 2.06 to 51.68, respectively. Heritability estimates expressed in percentage ranged from 26.00 % to 97.80 % and estimates of genetic advance ranged from 2.63 to 104. The genotypic correlation coefficients were higher in magnitude than that of phenotypic correlation coefficients for most of the traits under study, which clearly indicated the presence of inherent association among various characters. For yield per plant, significant positive correlation was estimated with vine length, pod length and pod weight, whereas significant negative correlation with branches per plant, days to first flowering and days to harvest. Significant GCA effects were recorded for all the characters except pod girth. Among the lines, KAU Deepika showed good general combining ability for days to first flowering, pod length, pod weight, 100 seed weight, yield per plant, yield per plot, days to harvest and keeping quality and among the testers, Manjari exhibited good GCA effect for vine length, pod length, pod weight, seeds per pod, pods per plant, yield per plant, yield per plot and keeping quality. Significant SCA effects were observed for 13 quantitative characters viz; vine length, primary branches per plant, terminal leaf length, terminal leaf width, lateral leaf length, lateral leaf width, days to first flowering, pod length, pod weight, 100 seed weight, and days to harvest, pod protein and keeping quality. Vyjayanthi x EC 18734, KAU Deepika x Manjari and KAU Mithra x Manjari were good specific combiners for pod weight and Vellayani Jyothika x EC 18734, Vyjayanthi x EC 18734, Githika x VU7 and KAU Deepika x Manjari for 100 seed weight. Desirable significant standard heterosis has been identified for 12 characters studied viz; no. of branches per plant, terminal leaf width, lateral leaf width, days to first flowering, days to harvest, pod weight, pods per plant, yield per plant, yield per plot, 100 seed weight, pod protein content and keeping quality. The crosses KAU Deepika x Manjari and KAU Mithra x Manjari registered significant positive heterosis over mid, better, and standard parents for pod yield and high mid-parent heterosis and standard heterosis for pods per plant. The highest magnitude of standard heterosis was identified for pods per plant (101.14 %), followed by yield per plant (75.30 %). Besides the heterotic potential, the hybrid KAU Mithra x Manjari, KAU Deepika x Manjari and Githika x Manjari were resistant to mosaic disease. In field evaluation during Rabi 2022, among the three testers, Manjari alone exhibited an immune response (VI-0.00) for mosaic disease. Other major pests and diseases observed in the field were pod borer, pod bug, fusarium wilt and anthracnose. The three crosses Githika x Manjari, KAU Deepika x Manjari and KAU Mithra x Manjari were selected and six generations i.e. P1, P2, F1, F2, BC1 and BC2 of each cross were evaluated under open field conditions to study the inheritance and gene action of mosaic resistance and yield parameters. For mosaic resistance, the scaling tests were non-significant which implied that additive-dominance model was adequate in Cross I and II, while dominance x dominance epistasis was prominent in cross III. Predominance of dominant gene action was noticed in cross II and III for yield per plant, while dominance x dominance (l) action in cross I. Duplicate type of epistasis was also observed in cross I and III for the trait. Epistatic interactions were observed for all the characters, except vine length and number of branches per plant in cross I (Githika x Manjari), additive x dominance being prominent in most of the traits. Predominance of dominant gene or dominance x dominance (l) interaction was noticed in majority of the traits in cross II ( KAU Deepika x Manjari). Significance of both additive x additive (i) component and dominance x dominance component or either one of the component was identified for the inheritance of yield traits in cross III (KAU Mithra x Manjari). Duplicate type of epistasis was revealed for eleven characters viz; vine length, terminal leaf length, lateral leaf length, days to flowering, pod girth, pod weight, hundred seed weight, yield per plant, crop duration, protein content and keeping quality, of which eight were present in cross II. The yard long bean hybrid KAU Deepika x Manjari, with good general combining ability for yield characters, high heterotic potential, high yield and mosaic resistance was identified as the best cross from the study.Item Breeding yard long bean(Vigna unguiculata subsp.sesquipedalis (L.) Verdcourt) for anthracnose resistance through conventional and molecular marker analysis(Department of Vegetable Science, College of Agriculture ,Vellayani, 2022-12-30) Merin Elza George; Sarada, SThe study entitled ―Breeding yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) for anthracnose resistance through conventional and molecular marker analysis‖ was carried out at the Department of Vegetable Science, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, during 2019-2022. The objective of the study was to identify molecular marker(s) linked with anthracnose disease resistance in the F2 segregating population of yard long bean, using bulk segregant analysis to enable marker assisted selection along with conventional breeding. The study was undertaken in six experiments. In experiment I, 50 genotypes of vegetable cowpea collected from different parts of India, including the released varieties of SAUs and ICAR institutes were screened against the most virulent isolate of Colletotricum gloeosporioides through artificial inoculation. Among the 50 genotypes tested, VU 53, with semi-trailing growth habit was found to be highly resistant with disease severity of 3.67 ± 0.13 %. Three susceptible, high yielding long podded varieties viz., KAU Deepika, Vellayani Jyothika and Githika, selected as female parents were crossed with VU 53, the most resistant genotype as male parent for the development of three hybrids. In experiment II, two crossing blocks were laid to produce the seeds of three hybrids and their F2 progenies. The three hybrids were evaluated along with the parents under replicated trial in the main field for trailing nature, yield and quality in experiment III. Significant variation was noticed on mean performance of yard long bean parents and hybrids for most of the characters studied. Earliest flowering was observed in KAU Deepika x VU 53 (57.33 ± 0.57 days) and delayed flowering in Githika x VU 53 (71.66 ± 1.15 days). Among the hybrids, the highest pod length was recorded in KAU Deepika x VU 53 (24.50 ± 1.00 cm), while the Vellayani Jyothika x VU 53 had the maximum pod girth (2.90 ± 0.10 cm). Maximum pod weight and pods per plant was recorded in KAU Deepika x VU 53 (19.22 ± 0.58 g and 79.33 ± 0.59 respectively) among hybrids. The cross Vellayani Jyothika x VU 53 (16.55 ± 0.20 g) exhibited maximum seed weight. Among the three hybrids, KAU Deepika x VU 53 (1416.00 ± 126.09 g) recorded the highest yield per plant and was on par with Githika x VU 53 (1343.33 ± 75.06 g). Among the hybrids, KAU Deepika x VU 53 (67.85 ± 0.96 days) was significantly superior for days to harvest. The longest duration among hybrids was observed in KAU Deepika x VU 53 (126.56 ± 0.37 days) and the shortest duration was recorded in Vellayani Jyothika x VU 53 (121.31 ± 0.58 days). High heritability and genetic advance was recorded for vine length, days to first flowering, pod length, pod weight, pods per plant, yield per plant, yield per plot, hundred seed weight and keeping quality. Yield per plant had significant positive phenotypic and genotypic correlation with pod weight, followed by pods per plant, length of terminal leaf, seeds per pod, pod length, crop duration, keeping quality and days to harvest. Pods per plant could be considered as the most important yield trait for enhancing the yield in yard long bean because of its high, positive correlation and direct effect with yield per plant along with high heritability and genetic advance. In experiment IV, parents, three hybrids and F2 progenies were evaluated for resistance to natural incidence of C. gloeosporioides in the main field, as unreplicated trial and without any plant protection measures. All the three F1 were found to be field tolerant. Out of 175 F2 plants of the cross KAU Deepika x VU 53, 164 plants were susceptible and 11 were resistant. In the case of Vellayani Jyothika x VU 53, 175 plants were susceptible among the 187 individual F2 progenies observed. Similarly, in the cross Githika x VU 53, 188 plants were susceptible while 12 plants were found to be symptomless. The F2 progenies of the high yielding hybrid KAU Deepika x VU 53 were evaluated for resistance to C. gloeosporioides through artificial inoculation in experiment V. Out of 196 plants, 185 plants were found to be susceptible whereas 11 plants were resistant which could be utilized in marker assisted breeding programme. The segregation for anthracnose resistance in F2 plants was in the ratio 15:1 (185 susceptible plants out of 196), which suggests that the inheritance of anthracnose resistance may be controlled by two recessive genes. Bulked segregant analysis was done using the DNA from the resistant parent, susceptible parent, resistant F2 bulk and susceptible F2 bulk in experiment VI. Bulked segregant analysis with the SSR primer CLM0008 revealed a polymorphic band at ≈ 300 bp which was appeared in the resistant parent and bulk. Bulked segregant analysis with ISSR primer UBC 811 produced polymorphic bands at ≈ 1100 bp, which were present in resistant parent and resistant bulks. The identified markers linked with resistance were validated over the resistant F2 lines obtained.