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ThesisItem Open Access Reproductive biology of water lily (Nymphaea nouchali Burm.f.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2012) Fahida, P K; KAU; Presanna KumariWater lilies are a group of fascinating aquatic perennial herb belonging to the genus Nymphaea. Among the different species of Nymphaea, Nymphaea nouchali is one common in south India. This species is commonly known as blue water lily, blue star water lily or star lotus. The plant is historically and functionally significant since it is associated with our culture and tradition. This species which forms an important constituent of aquatic flora possesses immense medicinal and ornamental values. Despite of its immense potentialities, water lily has received very little attention of crop improvement workers. Information on developmental pattern and reproductive biology which is fundamental for crop improvement programmes is lacking in this plant. Hence this investigation entitled ‘Reproductive biology of water lily (Nymphaea nouchali Burm.f.) was under taken up with the objective of elucidating the reproductive biology and developmental pattern of flowers and fruits in Nymphaea nouchali. Two flower colour variants of Nymphaea nouchali- blue and white types maintained in cement tanks were selected for the study. The study was conducted during 2010-2012 in the Department of Plant Breeding and genetics, College of Horticulture, Vellanikkara. The leaves of both the colour variants are simple, orbicular with sub-peltate lamina and deeply cleft near to the petiole base. The petiole of both the type was long, glabrous and brownish in colour with lamina floating on the water surface. The blue type was significantly superior to the white type for mean length of leaf as well as means width of leaf at middle and tip. In both the types it took almost six days for the flower bud to reach the water surface and the flower opening occurred nearly three days after the bud reaching the water surface. Even after the flower opening the pedicel elongation continued in both the types to an extent of 4 cm. Maximum growth rate of the pedicel was observed on the day just prior to the flower opening. The white type produced longer flower bud and thus larger flowers when compared to blue type. However the circumference of the flower bud was more for blue type. The flowers of both the types were faintly fragrant. The flowers opened in morning and closed in the evening hours and again opened on next day. The opening time of the flower varied from 7.30 am to 9.45 am. The closing time varied from 5.15 pm to 6.15 pm. Bright and sunny days favoured early opening of the flower. The blossom life was three days for blue type where as it was four days in white type. The flowers were produced throughout the year on an average of 3 to 4 days interval in both the types. Hence it can be well recommended for water gardens. The flowers were found to be solitary, pedicellate, and complete with various floral whorls in spiral fashion on the floral axis. Significant variability was observed on various floral characters among the two types. Each stamen consisted of a filament, anther and a sterile appendage at the tip. The initiation of dehiscence occurred by the longitudinal splitting of the anthers in both the types. The pollen dehiscence occurred only after complete opening of the flower. The stigma receptivity started 17 hours before flower opening and the receptivity was retained up to 20 hours after flower opening. Honey bees, house flies and weevils were found to be the major insects visiting the flowers. Several dead insects were observed in the stigmatic cup of both the types indicated the insectivorous nature of the flower. The pollen grains were found to be round, yellow in colour and monocolpate with reticulate exine in both the colour variants. No fruit or seed development were observed in both the colour variants. The absence of fruit or seed set can be attributed to very low fertility of the pollen and some incompatibility mechanisms in the flower. The vegetative propagation from leaf was found prominent in both the colour variants under study.ThesisItem Open Access Formation of core set in rice (Oryza sativa L.) short duration germplasm accessions(Department of plant breeding and genetics, College of horticulture, Vellanikkara, 2012) Pawan Saini; KAU; Rose Mary, FranciesRice (Oryza sativa L.) popularly known as ‘Global grain’ is the staple food for over half the world’s population. In Kerala, rice occupies the prime place among the food crops cultivated. Diversity of cropping systems, the edaphic and climatic variations found among and within different cropping regions have resulted in a cafeteria of variable genotypes. Concerted efforts by breeders in Kerala Agricultural University to conserve the diversity in rice crop, have resulted in formation of a germplasm collection of over 1000 accessions. Such large variability, though essential for crop improvement programmes, reduces the accessibility of germplasm and poses difficulty in making effective choice of parental material for breeding programmes. The concept of core collection proposed by Frankel (1984) provides a solution to this problem. According to him, core collection is defined as a representative sample of the entire collection with minimum repetitiveness and maximum genetic diversity of a crop species and its relatives. Considering the advantages in obtaining a subset that retains maximum diversity of the large germplasm collection, an effort was made to form a core set from a base collection of 160 short duration accessions (Base collection). The 160 accessions were raised in an Augmented Blocks Design, at College of Horticulture, Vellanikkara with 16 blocks during kharif 2011 -12. Each block comprised of 10 accessions (unreplicated) and 3 checks. The accessions were characterized and evaluated for 41 qualitative traits and 24 quantitative traits as per the descriptor of rice (Rani et al., 2004; IRRI 2007). Results revealed that wide variability existed in the Base collection for all the traits studied. A core set of 34 accessions was developed by using PowerCore (v.1.0) software based on 24 quantitative traits. The representativeness of diversity in base collection in the core set was evaluated through comparison of, i) estimates of mean for the quantitative trait through One sample‘t’ test, and ii) Levene’s F-test for variances. Chi-square test was employed to examine the parity in frequency distribution of morphological traits in the core set and Base collection. All the above tests proved that both the core set and Base collection did not differ significantly from each other. This indicated that variability in core set was on par with that found in the Base collection. Shannon-Weaver diversity index between Base collection and the core set was compared to assess the extent of diversity present in the two populations. Results revealed that core set comprising of 34 accessions has captured 100.54% of total diversity of the Base collection (160 accessions) which it was derived from. Thus, the core set proved to be a true representative of the diversity present in the Base collection. The reduced number greatly enhances accessibility of germplasm collection for breeding programmes aiming at improving yield and yield contributing traits.ThesisItem Open Access Genotype X environment interaction in aromatic rice (Oryza sativaL.) cultivars of Wayanad district of Kerala(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2012) Adheena Ram, A; KAU; Elsy, C RThe present study on “Genotype x Environment interaction in aromatic rice (Oryza sativa L.) cultivars of Wayanad district of Kerala” was carried out at the Department of Plant Breeding and Genetics, College of Horticulture, KAU, Vellanikkara during 2010 - 2012 aiming to characterize the aromatic rice cultivars (Gandhakasala and Jeerakasala) of Wayanad district based on morphological, cooking and biochemical characteristics, to assess the magnitude of G×E interaction and to analyse the stability over different environments. Gandhakasala and Jeerakasala are the most popular traditional aromatic cultivars of Wayanad district of Kerala. Out of the total 37 samples of aromatic genotypes collected from different areas of Wayanad district, eight Gandhakasala types and one Jeerakasala type were selected based on the grain characteristics like non pigmented apiculus, golden colour lemma and palea, white kernel colour, slender grains with partial awns (for Jeerakasala type) and awnless medium grains (for Gandhakasala type) and used along with check varieties for in depth study. These genotypes were evaluated at Wayanad and Idukki districts representing high altitude areas and at Palakkad district representing normal altitude area. Aromatic genotypes when compared with check varieties recorded more leaf length, culm length, days to 50 per cent flowering, days from seeding to harvest, panicle length, number of productive tillers and straw yield at all the three locations. In aromatic genotypes, the total duration was nearly 30 days less at Palakkad than at higher altitude areas. High level of spikelet sterility was observed at Idukki district in all the genotypes. Hence, grain yield and grain characteristics could not be recorded at Idukki district. Among the aromatic types, Jeerakasala type recorded significantly higher grain yield and 1000 grain weight than Gandhakasala types at Wayanad and Palakkad. The aromatic genotypes had less milling recovery than check varieties at both locations, indicating the need for specially designed machines for milling aromatic genotypes. At Wayanad, Gandhakasala types recorded high kernel elongation ratio and low volume expansion ratio (preferred grain characteristics for aromatic rice) compared to Jeerakasala type and check variety. In general, total carbohydrate content and protein content were low for aromatic types. The favorable characters of aromatic rice cultivars were more expressed at Wayanad district than at Palakkad district. At Wayanad, aromatic genotypes recorded low to intermediate amylose content. At Palakkad, all aromatic genotypes except GT 2 had low amylose content which can lead to stickiness of cooked rice. At Wayanad, most of the aromatic genotypes except GT 5 expressed moderate aroma. Whereas, at Palakkad the genotypes expressed slight aroma only, reducing its marketability. Grain length, 1000 grain weight, milling recovery per cent, amylose content and kernel elongation ratio were significantly high at Wayanad. Short and partial awns were the characteristic features of Jeerakasala grains, while awns were absent in Gandhakasala types and check varieties. Aromatic genotypes had white seed coat colour, whereas check varieties had red seed coat colour. Unusually high spikelet sterility recorded for all the genotypes when grown at Idukki was a pioneer report of such phenomenon leading to total crop loss from Kerala. Fertile spikelets were recorded from Wayanad and Palakkad districts. Studies on phenotypic and genotypic coefficient of variation revealed high level of variability for grain yield and 1000 grain weight and moderate level of variability for grain length, amylose content and protein content. Characters like leaf length, culm number, number of spikelets per panicle and straw yield indicated high heritability accompanied with high genetic advance at high altitude areas. Grain length and 1000 grain weight had significant positive correlation with grain yield. Whereas leaf length, culm length, days to 50 per cent flowering, days from seeding to harvest and panicle length had negative genotypic correlation with grain yield. At Wayanad and Palakkad, 1000 grain weight revealed high positive direct effect with grain yield. At Wayanad, JT 9 (Jeerakasala type), GT 3 and GT 8 (both Gandhakasala types) showed better performance based on high grain yield, high straw yield, intermediate amylose content and moderate aroma. The aroma and amylose content in aromatic genotypes were low at Palakkad district, hence further studies are needed to find out the suitability of cultivation of aromatic types in Palakkad district. Stability analysis for morphological characters recorded from three locations revealed that GT 6 had more adaptable characters over environments. GT 1 had more stable grain characters from recorded two locations. The predicted grain yield at Idukki was high for JT 9.ThesisItem Open Access Variability for yield and resistance to yellow vein mosaic virus disease in okra : Abelmoschus esculentus L. Moench(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2012) Kishor, D S; KAU; Arya, KThe present investigation on “Variability for yield and resistance to yellow vein mosaic virus disease in okra (Abelmoschus esculentus (L.) Moench)” was conducted at the Department of Plant Breeding and Genetics and Department of Plant Pathology, College of Agriculture, Vellayani during 2011-2012 and evaluation of germplasm for genetic variability, character association and resistance to yellow vein mosaic disease, confirmation of disease resistance in selected genotypes through vector and graft transmission studies, development and evaluation of F1’s for combining ability, heterosis and disease resistance were done. The okra germplasm consisting of thirty six accessions collected from different parts of Kerala and Karnataka was assessed for the extent of variability, heritability and genetic advance, the relationship among the yield and associated traits and disease scoring. Analysis of variance showed significant difference among the thirty six genotypes for all the characters studied. The germplasm possessed sufficient variability and offered scope for selection based on characters like plant height, number of primary branches, leaf axil bearing first fruit, duration, number of fruits per plant, fruit weight, fruit length and yield per plant. Five genotypes viz., AE-2 (IC 1012-1), AE-8 (Thirumala local), AE-28 (Halu Bhendi ), AE-32 (Kunnapuzha local)and AE-33 (Holavanalli local) exhibited resistance to YVMV during all the crop stages after scoring studies and resistance was confirmed to these selected ones by artificial transmission methods such as vector transmission and graft transmission in glass house. High genotypic and phenotypic coefficient of variation was noticed for almost all characters and narrow difference between GCV and PCV suggest that environmental influence is minimal for the traits studied. High estimates of heritability coupled with high to moderate genetic advance as percent over mean was recorded for all the characters considered. Yield had positive and significant association with number of fruits per plant, fruit weight, fruit girth and number of primary branches indicating that selection based on these characters may improve yield. In the line x tester analysis, the mean sum of squares due to genotypes was significant for all the characters studied. Combining ability analysis revealed higher magnitude of SCA variance for all the characters except days to first flowering and fruit girth indicating preponderance of non additive gene action. Among the hybrids cross combination Holavanalli local x Mallapalli local had high per se and sca effects for yield per plant, fruit length, fruit weight, number of fruits per plant, duration, plant height, number of primary branches, leaf axil bearing first fruit and days to first flowering and was considered as the superior hybrid followed by the cross combination Thirumala local x Punjab Phalgani which had high sca effects and standard heterosis for yield and yield contributing characters. These hybrids were also resistant to yellow vein mosaic virus disease. Based on per se performance for yield and disease resistance scores the hybrids Thirumala local x Kattakada local and Kunnapuzha local x Punjab Phalgani can also be considered as good hybrids. The cross combination Holavanalli local x Mallapalli local showed significant standard heterosis for all the characters and hence recommended for heterosis breeding.ThesisItem Open Access Induction of lodging resistance in upland rice (oryza sativa L.) through mutagenesis(Department of Plant Breeding and Genetics, Colllege of Horticulture, Vellanikkara, 2012) Jyothilekshmi, S; KAU; Dijee BastianAn investigation was undertaken at College of Horticulture, Kerala Agricultural University during 2010-2012 to develop desirable mutants in rice varieties Swarna Prabha and Vaishak and to analyse the extent of variability generated as a result of induced mutagenesis. The experimental material consisted of two rice varieties Swarna Prabha (PTB 43) and Vaishak (PTB 60), suited for upland growing conditions and mutation induction was carried out using gamma rays as physical mutagen and EMS as chemical mutagen. Physical mutagenesis was carried out for in vivo studies and chemical mutagenesis was carried out for in vitro studies. For in vivo mutagenesis the optimum dose of mutagen was fixed by germination test and seedling vigour test. LD50 value was estimated by probit analysis and for variety Swarna Prabha lethal dose was obtained at 426Gy and for Vaishak it was fixed at 398Gy. Based on the lethal dose, two effective doses were selected for both the varieties. 400 Gy and 450 Gy doses were selected for Swarna Prabha and 375 Gy and 450 Gy doses were selected for Vaishak. M2 was raised following pedigree method and observations were noted so as to assess the extent of variability generated as a result of mutation induction. Significant amount of variability was noted for panicles per plant, panicle length and plant height. Panicles per plant, plant height and days to maturity recorded high values for heritability along with low genetic advance and hence selection will be rewarding only in later generations. Mutants performed better than the parents for characters such as panicles per plant, panicle length, grain yield per plant, days to maturity, and harvest index. Association studies for yield related characters revealed significant intercorrelation for all the characters. Simple correlation was worked out for lodging resistance and from this it was noted that cellulose content is having highly significant positive correlation with lodging resistance. Four mutants in Swarna Prabha (mutant lines 27, 43, 44 and 56) and eleven mutants in Vaishak (mutant lines 77,132,135,144, 151, 157, 158, 95,103,121 and 152) were found to be promising with better yield and lodging resistance. For in vitro studies using EMS as chemical mutagen, in vitro protocol was initially standardized. Effective sterilization was obtained when the seeds were treated first with 70 per cent alcohol for two minutes followed by treatment with 0.1 per cent mercuric chloride for two minutes. Variety Vaishak was found to have better response to in vitro culture than the variety Swarna Prabha. Callus induction media was standardized using different concentrations of 2,4-D and Kinetin and callusing response was found to be higher in MS media supplemented with 2 mg/l 2,4-D and 0.5mg/l Kinetin. Callus subculture was also carried out in the same media composition and regenerationmedia used was MS + 2.0 mg/l NAA + 0.5 mg/l BAP + 4.0 mg/l Kinetin. Mutagenesis was carried out on three week old subcultured calli with different doses of EMS for varying duration so as to estimate the LD50 value. Treated calli was transferred to regeneration media and the responses were marked as 25 per cent browning, 50 per cent browning, 75 per cent browning, 100 per cent browning and no browning. With increase in treatment concentration and duration the calli showed variation in its morphology. The calli which retained white colour were transferred to regeneration medium but due to the effect of duration and concentration of EMS treatment no further response was noted in the regeneration medium.ThesisItem Open Access Evaluation of okra [Abelmoschus esculentus(L)Monench] genotypes for yield resistance to shoot and fruit borer,Earias vittella(Fab)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2012) Shrishail B, Duggi; KAU; Sunny K, OommenThe research project entitled “Evaluation of okra [Abelmoschus esculentus (L.) Moench] genotypes for yield and resistance to shoot and fruit borer, Earias vittella (Fab.)” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 2011-2012. The study aimed at the evaluation of a collection of okra genotypes for shoot and fruit borer resistance and yield to identify high yielding shoot and fruit borer resistant genotypes, if available among them. Thirty one genotypes of okra collected from different sources were evaluated for yield and resistance to shoot and fruit borer in a field experiment in randomized block design with three replications. Observations were recorded on 13 characters viz., days to 50% flowering, leaf axil bearing first fruit, number of primary branches, plant height, duration, number of fruits per plant, fruit weight, fruit length, fruit girth, yield per plant, shoot infestation, fruit infestation and number of larvae per 25 fruits. Analysis of variance revealed significant differences among the genotypes for all the thirteen characters studied. Also the genotypes showed wide variation for the shoot and fruit borer infestation. In this study, high values of PCV with correspondingly high values of GCV were observed for the characters viz., number of primary branches and number of fruits per plant which indicated the presence of substantial variability for these characters. High magnitude of heritability coupled with high genetic advance for the characters viz., yield per plant, number of fruits per plant, number of primary branches, fruit weight and fruit length suggested the scope for improvement of these characters through selection. Both at phenotypic and genotypic levels, yield per plant showed high positive correlation with number of fruits per plant, fruit weight and fruit girth which implies that selection for these characters would lead to simultaneous improvement for yield per plant in okra. In the present study, shoot and fruit borer resistance evaluation was done comparing the damage suffered by the accessions consequent to natural infestation under field condition. Significant differences were observed among the genotypes for all the damage parameters employed for resistance evaluation viz., percentage shoot infestation, percentage fruit infestation and larval count in 25 fruits. Fruit damage in terms of both percentage fruit infestation and larval count in 25 fruits was highest for T1 and lowest for T9. The genotypes T22 and T23 recorded the lowest percentage shoot infestation. Highest percentage shoot infestation was observed for genotypes T16 and T24. The genotypes T1, T2, T24 and T25 were found to suffer severe damage on all the three damage assessment criteria employed. Fruit damage assessed based on percentage fruit infestation as well as larval count in fruits indicated T9 as the accession suffering the least fruit damage irrespective of the criterion employed for damage assessment. However, T9 was found to suffer significantly higher shoot damage in comparison with T22 and T23, the genotypes suffering least shoot damage. But the fruits of T22 and T23 were found to be severely attacked by the pest. Overall consideration of damage measurements indicate T9 as a worthwhile genotype with regard to shoot and fruit borer resistance. This notion is further supported by the result of the laboratory experiment conducted to get an insight into the larval feeding preferences which suggested T9 as the accession least preferred by the larvae for feeding. Highly significant positive genotypic correlation between per cent fruit infestation and larval count in the fruits evident from the present study suggests that either of the fruit damage criteria may be employed for the evaluation of shoot and fruit borer resistance in okra. T15 was the highest yielder among the accessions evaluated but found to suffer considerable damage from shoot and fruit borer infestation. On the other hand, T9 adjudged as the accession with the highest level of resistance to the pest was poor yielding. Combination breeding efforts utilizing T15, the highest yielder among the accessions evaluated and T9 as the shoot and fruit borer resistance source would hopefully lead to development of high yielding shoot and fruit borer resistant genotypes of okra.