PG Thesis
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Item Interspecific Hybridisation in Sorghum(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2005) Jithesh, V G; Suma Bai, D IA 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.Item Combining ability in grass cowpea [Vigna unguiculata var- sesquipedails](Department of Plant Breeding, College of Agriculture, Vellayani, 1992) Rejatha, V; Ramachandra Nair, NTwo lines, six testers and twelve bybrids of cowpea were evaluated in the partially shaded conditions of coconut garden of Vellayani for combining ability and gene action. The lines and testers were selected based on their previous performance and crossed in line x tester manner to get twelve hybrids. Observations were made on sixteen characters of which twelve characters showed significant differences among the twenty treatments. Combining ability analysis was carried out as suggested by kempthorn (1957) suggested the importance of specific combining ability for all the characters except for length of pod and days to flowering. It was seen that the varieties chharodi – 1, Culture – 9, V – 26 and GC – 82 – 7 were the best general combiners and the cross combinations Chharodi – 1 x V – 26, Chharodi – 1 x Kanakamani and Culture – 9 x V – 322 were the best specific combinations for yield and yield attributes under partially shaded upland conditions. The yield and important yield attributes were under the control of non – additive gene actions except days to flowering and length of pod. The varieties Culture – 9, GC – 82 – 7,Chharodi – 1 and V – 26 and the cross combinations Chharodi–1 x V–26, Chharodi-1 x Kanakamani and Culture –9 x Kanakamani can be further exploited through selection.Item Genetic analysis in F2 And F3 progenies of selected crosses of rice varieties of diverse origin(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2000) Faseela, K V; Rajan, SThe research project 'Genetic Analysis in F2 and F3 Progenies of Selected Crosses of Rice Varieties of Diverse Origin' was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur durinq the period January to December, 1998. The major objectives of the study were to understand the various genetic parameters of characters under study, identification of yi&ld components and formulation of selection model so as to isolate promising lines having desirable ideotypic features • from the segregating generations. The high yielding varieties developed from such lines will have a broad genetic base as the parents of selected crosses are of diverse origin. Components of heritable variation revealed that the characters showed decreased trend of variability from F2 to F3. PCV was higher than GCV in both generations for all the characters studied. Low PCV and GCV were observed for grain length, panicle length and duration to 50% flowering in both generations, while grain density showed low PCV and GCV in F3 only. In general, broad sense heritability estimates were observed to be higher in F2 than F3. The characters, plant height at harvest, total tillers plant", LIB ratio, 1000 grain weight, secondary branches panicle' and tertiary branches panicle:' provided great help in direct selection from phenotypic performance, as they exhibited higher values of genotypic coefficient of variation, heritability and expected genetic advance. The .. character, grain length showed little scope of improvement through selection due to low GCV and GA . • Correlation studies in F2 and F3 revealed that positive correlation existed between yield and component characters, namely, total tillers, panicle bearing tillers and tertiary branches panicle". Negative correlation was observed for 1000 grain weight with yield in both the generations. Panicle length and duration to 50% flowering exhibited absence of association with yield in F2 and F3, which indicate that these traits can be recombined as desired. In F3, LIB ratio and grain length exhibited positive correlation and grain breadth exhibited negative correlation, with yield, while these characters showed absence of association with yield in F2• Plant height and number of grains panicle:' exhibited negative association with yield in F2 where as number of grains panic!e' exerted positive association with yield in F3 and plant height showed absence of association with yield in F3. Genotypic correlation among di~ferent yield components in F2 and F3 revealed that semidwarf plants with higher number of productive tillers produced grains with higher LIB ratio and lesser grain weight, which in turn increased the yield. The study also showed that, when number of grains and compactness of• panicles increase, grains become more slender with reduced grain weight. Study of path coefficient analysis revealed that all the characters influenced the yield directly or indirectlv through some other traits. The correlation and path analysis study suggested that during selection, breeder should give emphasis on" semidwarf olant stature, higher number of productive tillers, compact panicles, reduced number of secondary branches, high LIB ratio of grains with reduced density and weight. A selection model was formulated consisting of the characters, , namely, yield ha:'. total tillers plant". LIB ratio, grain breadth and grain density. Using this model, ranking of 105 genotypes in F3 was done and identified that the accessions, V 82 and V 89' belonging to lA 36 x Mattathriveni, were the best genotypes. Study revealed that all the four crosses namely, Vytilla 3 x Mattathriveni, Vytilla 3 x Kaohsiung Sen Vu 338, Mattathriveni x Mahsuri and lA 36 x Mattathriveni, were promising enough to derive superior segregants, the best among them being IR 36 x Mattathriveni. The plants with red kernel, identified in F3 of the cross IR 36 x Mattathriveni, can be used for the development of high yielding varieties with red kernel and preferable cooking qualities suited to Keralites, as well as resistance to biotic and abiotic stresses. This investigation also suggested that crosses from parents of diverse origin will broaden the genetic base of the varieties to be developed in future and will help to break the yield plateau in rice.Item Development of stabilised population of cowpea segregants(Vigna unguiculata (L.) walp.) with high protein content and grain yield(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2019) Ashni Varghese; Jiji JosephCowpea (Vigna unguiculata (L.) Walp.) is an important pulse crop providing good source of protein and often referred to as poor man’s meat. It is a versatile crop, of which seeds are utilised as pulse, green pods as vegetable, leaves as forage and helps in restoring soil fertility. Many reports have indicated protein content of more than 30 per cent in certain cowpea genotypes, but at the cost of yield. Hence, the present study was proposed to develop cultures with high grain yield and protein content. The present study was conducted at Department of Plant Breeding and Genetics, College of Horticulture during 2017-2019. Twenty three lines with high yield and protein content in the F3 generation of two cowpea crosses H10 (Anaswara X PKB 3) and H11 (Anaswara X PKB 4) identified in previous studies formed the working material. These lines were evaluated in F4, F5 and F6 generations and pedigree selection was performed to select superior plants. Observations were recorded on 12 characters viz. plant height, number of branches, days to first flowering, days to first harvest, days to last harvest, number of pods per plant, length of pod, pod weight, number of seeds per pod, hundred seed weight, grain yield per plant and protein content. The F4 generation of both the crosses exhibited lower mean value for most of the characters than the parent Anaswara, but recorded moderate to high variance and range. Higher mean value was observed for days to first flowering, first harvest, last harvest, number of branches and protein content. Genetic parameters indicated that GCV was moderate for length of pod, number of seeds per pod, and hundred seed weight and high for grain yield per plant. High heritability coupled with moderate to high genetic advance was recorded for number of pods per plant, number of seeds per pod, hundred seed weight, and grain yield. Correlation studies in F4 generation revealed that grain yield was positively correlated with plant height, number of branches per plant, number of pods per plant, length of pod, pod weight, number of seeds per pod and test weight. There was non-significant correlation between grain yield and seed protein content. Further path analysis confirmed that high positive direct effect on grain yield was given by pods per plant, number of seeds per pod and hundred seed weight. Based on these observations, characters like number of pods per plant, hundred seed weight and number of seeds per pod were simultaneously included along with grain yield for setting selection criteria to select superior individual plants. Based on these set criteria, 13 individual plants from cross H10 and 10 plants from cross H11 were selected and forwarded to F5 generation. In F5 generation, mean values for number of branches, number of pods per plant, number of seeds per pod and protein content were higher than that of Anaswara with sufficient variance and range. GCV was moderate for number of branches, length of pod, pod weight, hundred seed weight and grain yield per plant. High heritability with moderate to high genetic advance was recorded for number of pods per plant, length of pod, pod weight, number of seeds per pod, hundred seed weight and grain yield. Based on the segregation pattern observed, the plants were grouped into two different categories - one with medium long pods and small seeds closely packed within the pod and the other type with long fleshy pods and bold seeds. Hence, separate selection criteria was developed for both the types comprising of characters like number of pods, number of seeds per pod, pod length, hundred seed weight, grain yield and protein content. Based on these set criteria, five individual plants from cross H10 (one type 1 and four type 2) and 17 plants from cross H11 (five type 1 and twelve type 2) were selected and forwarded to F6 generation. In F6 generation, mean value was higher than Anaswara for number of pods per plant but lower for plant height, days to first flowering, days to first harvest, days to last harvest, pod length and hundred seed weight. For other characters, mean value was comparable to Anaswara. Moderate GCV value was recorded for length of pod, pod weight and hundred seed weight. High heritability with high genetic advance was recorded for length of pod, pod weight and hundred seed weight. Separate selection criteria was developed for the two categories of plants and total five individual plants were selected, one from cross H10 and four from cross H11. The selected plants from F6 generation were subjected to organoleptic evaluation to find its suitability to be used for vegetable purpose. Three plants of type 2 and one plant from type 1 were found promising. The identified lines, H11-3.9-1-7-13-7, H11-3.9-1-1-18-13, H11-49.7-1-8-10-15, H10-71-16-1-9-15-12, and H11-2-20-3-14-16-12 can be evaluated in replicated yield trials and tested for stability over locations and seasonsItem Hybridization using promising second generation inbred and molecular characterization of a the third generation inbreds of WCT coconut(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2018) Hassain, N; Sujatha, RThe research project entitled “Hybridization using promising second generation inbred and molecular characterization of the third generation inbreds of WCT coconut (Cocos nucifera L.)” was carried out in the Department of Plant Breeding & Genetics, College of Agriculture, Padannakkad during the year 2016-2018. The major objectives of this study include development of D x T hybrids using promising palms in second generation (S2) inbreds of West Coast Tall (WCT) as male parent and Malayan Yellow Dwarf (MYD) as female parent and characterization of third generation (S3) inbred seedlings of superior S2 palms of WCT using RAPD analysis. For hybridisation, the male parent was selected from the superior inbred family based on the reports on morphological evaluation and estimation of inbreeding depression during the period 2013-2015 (Chethana, 2016). The family IIIS2-1 showed lowest inbreeding depression for yield related traits among 12 families followed by VS2-2. The palm 313 (IIIS2-1) and 225 (VS2-2) were selected as male parents. Superior MYD palm to be used as the female parent was selected from among the MYD palms available at CoA, Padannakkad based on the general features of mother palm selection (Nair et al., 2008). Observations were recorded from these parental palms which included 24 morphological characters. The male parents showed inbreeding depression for several vegetative characters such as stem girth, functional leaves etc and reproductive characters such as number of female flowers per inflorescence, setting percent and nut yield per palm per year, compared to WCT. The results showed that inbreeding depression for these characters was more in palm 313 (developed by selfing) than palm 225 (developed by sibmating). Total five nuts were harvested from MYD (two nuts by using pollen from palm 313 and three nuts using pollen from palm 225) during May 2018 and were sown in the nursery. Molecular characterization of the 15nos of S3 inbred seedlings of IIIS2 family planted in the field in replicated plots were done using RAPD. Genomic DNA was isolated from 15 seedlings of IIIS3 family among which 10 were produced by selfing the S2 palms (IIIS3-1) and 5 were produced by sibmating the S2 palms (IIIS3-2) along with COD, CGD and WCT. After DNA isolation, samples were subjected to RAPD analysis using 10 decamer primers namely OPAU02, OPBA3, OPAW14, OPAW19, OPAW12, OPAW13, OPAW13, OPAW09, OPAU03, OPAW08 and OPAW15 selected based on screening 30 primers. Using primer OPAW08, a band of size of ~400bp was specifically found in inbreds alone while it was absent in dwarfs and WCT seedlings. In OPAU 03 primer, band size of ~1200bp was absent in WCT but present in all inbreds and CGD. The sibmated inbred NL1 showed a distict pattern when amplified with OPAW 09 compared to all other inbreds. The primer produced a specific band of size ~1050bp only in the sibmated inbred CL1 and was absent in all other samples. Amplification with OPAW19 primer produced a banding pattern in which it mainly distinguished CGD from all other seedlings where there were only two bands while others were having six bands. Primer OPAU 02 produced two unique amplicons: 1100bp present in selfed inbred I1M1 TH2 and MYD; 1000bp present in COD and MYD. Genetic similarity among the 15 IIIS3 seedlings, CGD, COD, MYD and WCT was estimated by using of software DARwin (Darwin 6.Ink). The dendrogram indicated three major clusters in which the grouping of several inbreds along with WCT, COD and CGD may be an indication supporting the hypothesis that the dwarfs might have been originated from the talls during the course of evolution followed by selection. The two dwarfs present in the group are COD and CGD which are from Chavakkad area in Kerala and WCT is the most common cultivar of Kerala. As a future line of study, further evaluation of these S3 inbreds regarding the flowering time and yield characters has to be carried out to find out the genetic potential of these inbreds as breeding lines for producing superior hybrids. The seedlings to be emerged from the hybrid nuts produced in the present study, though limited in number, needs to be evaluated for important traits and the hybridisation programme using superior palms in S2 generation needs to be continued for production of more number of hybrid nuts.