1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Genetic divergence in kiriyat (Andrographis paniculata Nees)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Prathibha, S S; Arya, KItem Ecophysiology and screening for climate change resilience in Mango (Mangifera indica L.) genotypes(Department of Pomology and Floriculture College of Agriculture,Vellayani, 2019) Aswini, A; Jyothi BhaskarItem 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 Breeding for lodging resistance in rice (Oryza sativa L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2019) Keerthiraj, B; Biju, SThe research work ‘Breeding for lodging resistance in rice (Oryza sativa L.)’ was conducted in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during the academic year 2017-2019. The research work was divided into three experiments. Experiment 1, consisted of screening of twenty-one rice genotypes for lodging resistance which was conducted at Agricultural Research Station (ARS), Mannuthy. After screening, three lodging resistant rice genotypes were selected and crossed in Line x Tester pattern with four lodging prone high yielding varieties, in experiment 2. In experiment 3, progenies were evaluated along with parents for lodging resistance. Lodging and other characters were measured based on Standard Evaluation System of Rice, developed by International Rice Research Institute (SES-IRRI), 2014. Wide variability existed among twenty-one genotypes for yield and most of the yield attributes studied, indicating ample scope for the improvement through selection. High heritability coupled with high genetic advance as per cent of mean indicating the influence of additive gene action in the expression of trait were observed for all the traits viz., days to fifty per cent flowering, plant height, flag leaf width, flag leaf length, tillers per plant, internodal length, culm diameter, culm wall thickness, days to maturity, panicle length, panicles per plant, panicle weight, seeds per panicle, test weight, silicon content, potassium content, seed yield per plant, and lodging per cent. Seed yield per plant recorded positive correlation at genotypic level with number of tillers per plant, number of panicles per plant, test weight, and silicon content. Lodging per cent exhibited positive correlation at genotypic level with days to fifty per cent flowering, plant height, flag leaf length, internodal length, culm diameter, days to maturity, and panicle length. At the same time, it was negatively associated with culm wall thickness, silicon content and potassium content. Based on experiment 1, four genotypes viz., Swetha (L1), Prathyasha (L2), Vaisakh (L3) and Ponmani (L4) were selected as lines. Three genotypes viz., Uma (T1), Gouri (T2) and Pournami (T3) were selected as testers. Evaluation of hybrids based on mean performance revealed that, hybrids H3, H5, H6, H9, and H12 recorded reduced lodging and H7, H8, H10, and H11 recorded moderate lodging. Based on scoring, for all the characters, the hybrids H1 (L1 x T1), H3 (L1 x T3), H5 (L2 x T2), H7 (L3 x T1), H8 (L3 x T2), H10 (L4 x T1), H11 (L4 x T2), and H12 (L4 x T3) showed high values. Estimation of gca effects of parents indicated that, L4, T1 and T3 were better combiners for reduced lodging. Based on all eighteen characters, L4, T1 and T2 were found as better combiners. Considering the scores, of mean performance and combining ability effects for all the characters together, L4, T1, T2, and T3 were found as the most promising parents. Specific combining ability effects studied among the cross combinations and scores indicated that, out of the twelve hybrids, H3 recorded high lodging resistance, and except H1 all others recorded moderate lodging resistance. Based on all the characters considered together, H1, H3, H5, H6, H8, and H10 recorded as better cross combinations. When scores of mean performances and sca effect were considered together for all the characters, hybrids H1, H3, H5, H8, H10, and H11 had high scores, and H6, H7, and H12 scored moderate scores. All the twelve hybrids recorded high significant heterosis for days to fifty per cent flowering, plant height, days to maturity, internodal length and lodging per cent. Scoring for both mean performance and heterotic effect for all the characters, revealed that, the hybrids H12 recorded highest score followed by H10, H11, H8, H3, H5 and H1. Evaluation of hybrids based on scores of mean performances, sca effects and heterosis for all the traits, revealed that, hybrid H10 stands in first position, H8 in second and H11 and H5 in third position. Among these, H10 (Ponmani x Uma) and H11 (Ponmani x Gouri) were found as better cross combinations. The identified hybrids can be evaluated in segregating generations for yield and reduced lodging.Item Diversity analysis in landraces of rice(oryza sativa L.) in Wayanad through morphological and molecular polymorphism study(Department of Plant Breeding and Genetics,College of Horticulture, Vellanikkara, Thrissur, 2018) Manjunatha, G A; Elsy, C RThe present investigation entitled “Diversity analysis in landraces of rice (Oryza sativa L.) in Wayanad through morphological and molecular polymorphism study” was conducted at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, Thrissur and Regional Agricultural Research Station, Ambalavayal, Wayanad during the period 2015- 2018. The study aimed to collect and characterize the rice landraces of Wayanad at morphological level and also to characterize the popular aromatic genotypes of the area at molecular level. DUS characterization revealed that, all the landraces under the study exhibited presence of leaf collar, absence of anthocyanin colouration of leaf collar, presence of leaf ligule, split shape of leaf ligule, absence of anthocyanin colouration for plant parts like lemma (keel), area below apex of lemma, stem nodes and presence of secondary branching in panicle. Variability was exhibited for majority of characters namely coleoptile colour, basal leaf sheath colour, intensity of green colour of leaf, anthocyanin colouration of plant parts like leaf, leaf sheath, auricles, ligules, lemma apex, area below apex of lemma, distribution of anthocyanin colouration in leaf, pubescence of leaf blade surface, leaf auricles, culm attitude, density of pubescence of lemma, colour of stigma, attitude of flag leaf blade, curvature of main axis of panicle, lemma and palea colour, presence and colour of awns, distribution of awns in panicle, secondary branching in panicle, attitude of branches in panicle, panicle exsertion, leaf senescence, sterile lemma colour, shape, colour and aroma of decorticated grain, gelatinization temperature and lodging nature.Thavalakannan, Mullan puncha and Sugandhamathi exhibited distinct morphological characters. Among the 60 landraces, Kanni kayama, Ambalavayal-1, Kothandan, Onamottan, Thondi-2, Chenthadi, Kannali and Thondi-1 exhibited significantly high grain yield per plant, which was on par with that of Uma and Aathira (high yielding check varieties), indicating the possibility of commercial cultivation of these cultivars. High PCV value than GCV for all the characters under study, indicated the influences of environmental factors on the characters. High heritability and high genetic gain was exhibited by the characters like length of leaf blade, width of leaf blade, stem thickness, stem length, number of tillers per plant, number of panicles per plant, length of panicle main axis, number of spikelets per panicle, number of grains per panicle, seed setting (per cent), 1000 grain weight, grain length, grain L/B ratio, decorticated grain L/B ratio and grain yield per plant, indicating that these characters could be used in crop improvement programmes. Character association studies including correlation and path-analysis revealed that, five characters viz., width of leaf blade, stem length, number of panicles per plant, weight of 1000 grains and decorticated grain width showed both positive correlation and positive direct effect on grain yield per plant. Cluster analysis based on qualitative characters categorized 60 landraces into 11 clusters at 74 percent similarity level. Based on D2 statistics analysis, the landraces were grouped into seven clusters with variable number of landraces in each cluster, indicating wide genetic diversity in the Wayanad landraces. All the inter-cluster distances were higher than the intra-cluster distance, indicating the wider genetic diversity among landraces of different clusters. Molecular characterization of aromatic rice genotypes of Wayanad by SSR (RM) profiling revealed high level of genetic polymorphism among the genotypes studied. Out of 86 SSR markers used for molecular characterization, 44 markers were polymorphic and remaining 42 were monomorphic. Maximum number of amplicons was exhibited by RM247 with five amplicons, followed by RM85, RM251, RM248 and RM493 with four amplicons each. The highest PIC value was exhibited by RM247 (0.90), followed by RM85, RM251 and RM493 with 0.88 PIC value each. Out of 86 SSR (RM) markers, 21 markers distinguished Basmati from traditional aromatic landraces of Wayanad viz., Gandhakasala and Jeerakasala. Seven SSR markers distinguished Gandhakasala from Jeerakasala, whereas 23 markers distinguished Basmati from Jeerakasala. Twenty-two markers distinguished Basmati from Gandhakasala and 23 markers distinguished aromatic group from non-aromatic group. Cluster analysis for molecular characterization revealed maximum similarity coefficient (1.00) within all the Jeerakasala morphotypes and all the Gandhakasala morphotypes. Cluster analysis effectively differentiated Basmati, Jeerakasala, Gandhakasala, Uma and Aathira from each other. Among the five clusters formed, cluster III was the largest one comprising all the 12 Gandhakasala morphotypes, followed by cluster IV with all Jeerakasala morphotypes. Cluster I, Cluster II and Cluster V exhibited one genotype each namely Aathira, Uma and Basmati, indicating their genetic distinctness.Item Performance analysis of vegetable soybean (Glycine max L.) in humid tropics(Department of Vegetable Science,College of Horticulture, Vellanikkara, 2018) Shilpashree, N; Nirmala Devi, SItem Induced mutagenesis for delayed flowering and high tillering in guinea grass (Panicum maximum Jacq.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Sudrik Bibhishan Popat; Mareen AbrahamItem Development of parthenocarpic gynoecious hybrids in cucumber (Cucumis sativus L.) for protected cultivation(Department of Olericulture, College of Horticulture, Vellanikkara, 2017) Ajay Bhardwaj; Pradeepkumar, TItem Evaluation of tomato (Solanum lycopersicum L.) hybrids for yield and bacterial wilt resistance(Department of Olericulture, College of Agriculture, Vellayani, 2017) Shashidhar M Sonnad; Sarada, SItem Genetic stock development for phytophthora pod rot disease resistance in cocoa (Theobroma cacao L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2017) Veeresh S Akki; Minimol, J SCocoa production is ruthlessly affected by pod rot disease caused by many Phytophthora species. Among these, the pod rot caused by Phytophthora palmivora is of prime importance. Since, the disease infection period is rainy season, the application of fungicides has not evidenced as a successful control measure. Hence, the effective and eco-friendly way to tackle this disease is by developing resistant varieties. The success of any breeding programme depends upon the availability of well characterised genetic resources. In this context, the current study was formulated for characterisation of exotic germplasm and identifying genetic stock of cocoa for Phytophthora pod rot resistance. Morphological characterization of 30 genotypes were carried out by recording ten qualitative and 23 quantitative characters governing leaf, flower, pod and bean. High variability was observed for most of the characters except petal colour and number of ridges and furrows. The germplasm when characterized based on biochemical parameters such as fat, polyphenols and mineral content (Na, K and Ca) also expressed wide variability. It is essential to quantify the diversity available among genotypes in order to design an effective breeding programme. Hence, cluster analysis was carried out by D2 statistics and principal component analysis. Among all the qualitative clusters, cluster III was the biggest with eight members. Cluster analysis of quantitative characters showed that most of the genotypes were placed separately in distinct cluster due to wide variability available in the germplasm. Cluster analysis of biochemical characters also exhibited wide variability which is evident from the fact that it formed 15 clusters even at 25 per cent similarity. Correlation studies and path analysis were employed to know the nature and relationships among the yield attributing characters. Here, it was found that wet bean weight (g) showed positive correlation with pod weight (g), furrow thickness (cm), pod length (cm), pod breadth (cm), weight of the bean (g) and number of beans per pod. Results of path analysis revealed that total wet bean weight (g) was directly influenced by pod thickness (cm), number of beans per pod, single dry bean weight (g) and wet bean weight (g). Since, quantitative and qualitative descriptors serve as an effective tool to discriminate among the genotypes, a evaluation data was constructed for all the genotypes considering distinct characters governing them. The non-pricking and pricking methods of pod inoculation with pure culture of pathogen were employed to know the disease resistance reaction exhibited by different genotypes. In the non-pricking method, five genotypes (ICS 41, SIAL 339, PNG 250, PNG 336 and IMC 20) with zero per cent infection and 14 genotypes (CRU 12, MO 109, GDL 7, GU 261/P, NA 149, PA 156, LX 43, POUND 4/B, JA 10/12, DOM 14, ICS 75, DOM 25, POUND 18 and POUND 16/A) with infection less than 15 per cent were grouped under highly resistant category. However, these genotypes did not show same disease resistance reaction in pricking method which indicated that the resistance was influenced by certain morphological characters apart from the internal resistance and the significance of those morphological characters were lost when pods were pricked. Binomial logistic regression revealed that different phenes like ridge thickness, polyphenol content and calcium content were positively contributing to disease resistance. Whereas, phenes like pod rugosity, pod basal constriction and pod length were negatively correlated with disease resistance. If these phenes are considered for selection, ample increase in the level of resistance will be noticed in the resultant population. Genetic stock was developed considering disease resistance and yield. As opined by many scientists “Disease resistance is a double-edged sword”. The phytotoxin developed in plants against pathogen is not only toxic to the pathogen but also to the plants resulting in yield reduction. Here also same trend was noticed and majority of the genotypes which expressed high resistance were low yielders. The accessions manifested high resistance can be used for further breeding programme.