Browsing by Author "Presanna Kumari, K T"

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Breeding biology and cross compatibility of close wild relatives of brinjal (Solanum melongena L.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2016) Neeraja Puthiamadom; KAU; Presanna Kumari, K T
The present study entitled “Breeding biology and cross compatibility of close wild relatives of brinjal (Solanum melongena L.)” was carried out in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during 2014 – 2016. The objective of the study was to elucidate the reproductive biology of the related wild species of brinjal and to ascertain their cross compatibility with the cultivated species. Four wild species variants of Solanum viz., viarum, gilo, incanum and indicum, collected from NBPGR, RS, Vellanikkara along with S. melongena varieties Haritha and Surya formed the material for the study. These genotypes were evaluated for various vegetative, floral and fruit characters following the descriptor developed by IPGRI (1988) and clustering was done. Study of the reproductive biology revealed that flowering was profuse in S. viarum, S.incanum and S. gilo. However S. indicum did not flower during the entire experiment period and hence could not be utilized in the programme. The flowers of Solanum species were found to be positively geotropic with a floral formula of ♀∕K(5)C(5)A(5)G(2). In all the species evaluated, flowers were pedicellate, zygomorphic, bisexual and complete. Irrespective of species, long, medium and short styled flowers were observed. However, the frequency of medium styled flowers were very low. Unlike in the case of S. gilo and S. melongena variety Haritha, a change in colour of the corolla was observed in S. viarum, S. incanum and S. melongena variety Surya on the day prior to anthesis. The time of anther dehiscence was found to vary with the species. The pollen grains dehisced nearly two to five hours after flower opening in S. viarum and S. incanum. However, in the cultivated varieties, Haritha and Surya, anther dehiscence commenced along with the opening of flowers. Among the different species protandry was observed only in S. gilo. The dehiscence continued for three days in all the species. Irrespective of species, pollen grains were remained fertile for three days. The change in the colour of the stigmatic surface from glossy green to deep yellow, at the time of initiation of stigma receptivity was a unique feature of S. gilo. In all the other wild species of Solanum as well as the cultivated varieties Haritha and Surya, the colour of the stigmatic surface was glossy green at the time of receptivity. The colour was found to fade with the decline in receptivity. Studies to assess the mode of pollination revealed that cross pollination is the rule in Solanum species. Cross compatibility studies were undertaken between the three wild species which flowered and the two cultivated types under S. melongena. Among the twelve crosses attempted, Surya x S. viarum, S. viarum x Surya, Surya x S. incanum, Haritha x S. incanum, S. incanum x Haritha, S. viarum x Haritha were the successful ones. Out of these, the progeny of three crosses viz., Surya x S. viarum, S. viarum x Surya and Surya x S. incanum established in the field. The progeny of the cross Surya x S. viarum was found to be superior with respect to fruit weight as well as absence of prickles on leaf and fruit pedicel. Even though one of the parents of this cross, Surya was susceptible to most of the common pests and diseases of brinjal, no incidence of pests and diseases was noticed in the progeny population
Estimation of genetic parameters in green gram (Phaseolus aureus Roxb.)
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Presanna Kumari, K T; Mary K George
Biometric studies on fifteen divergent green gram varieties (Phaseolus aurreus Roxb. syn. Vigna radiata (L.) wilzeck.) was conducted at the College of Agriculture , Vellayani , during November- January, 1979-80, to estimate the important genetic parameters like mean, range, genotypic and phenotypic coefficientsof variation , heritability, genetic advance and genetic gain and to find out the direct and indirect contributions of various component characters on yield by path coefficient analysis. There were significant differences among the varieties for all characters studied. Genotypic coefficient of variation was maximum for number of branches per plant followed by 100 seed weight and minimum for days to 50 per cent flowering . High heritability estimates were observed for pod length , 100 seed weight, plant height, number of seeds per pod days to 50 per cent flowering and number of pods per plant. Genetic gain was maximum for number of branches per plant followedby 100 seed weight and minimum for days to 50 per cent flowering. The number of branches per plant 100 seed weight, number of pods per plant and pod length had high heritability and genetic gain indicating the presence of additive gene action and hence they can be relied upon in selection programmes.
Morphogenesis and reproductive biology of water lily (Nymphaea spp.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Tincy Tom; Presanna Kumari, K T
Genus Nymphaea forms a complicated group of aquatic perennials having immense ornamental and medicinal value. Two phenological groups based on flowering viz., diurnals and nocturnals are recognized in this genus. Information on the reproductive biology and developmental features specific to the phenological groups are lacking in this genus. The present study entitled “Morphogenesis and reproductive biology of water lily (Nymphaea spp.)” was taken up in this background in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during 2013-2015 for elucidating and comparing the reproductive biology and developmental pattern of leaves, flowers and fruits in day as well as night blooming types of Nymphaea. A survey was conducted in the water lily growing tracts of Thrissur district and 12 accessions were collected. Five among these accessions were selected based on blooming time and seed set for further detailed evaluation. Growth and development pattern of leaves and flowers were observed to be uniform in all the accessions. However, the accessions differed in the number of days taken by the leaf and flower bud to reach the water surface and maturity. The rate of elongation of the petiole was significantly and positively correlated with sunshine hours and maximum temperature. There was no significant correlation between pedicel elongation and weather parameters. The leaves in all the accessions evaluated were simple orbicular with subpeltate lamina which was deeply cleft near to the petiole base. However, there was variability in the colour, margin and tip of the lamina. The night bloomers could be easily distinguished by the sinuately dentate margin and thick prominent veins on the abaxial surface of the lamina. Flowers were pedicellate and complete with all the floral whorls in a spiral fashion on the floral axis. Significant variability in both qualitative and quantitative characters were observed among the accessions for floral characters. The night bloomers differed from the day bloomers in having larger flowers with stamens devoid of appendages. Besides, the sepals were observed to have five to six prominent nerves on both sides. The flower opened in the morning and closed in the evening in day blooming types. In night bloomers the flower opening was in the evening hours and closing in the morning hours. The time of opening and closing further varied with the accessions. The process of opening and closing continued for four days and on the fifth day the flower submerged in water. The anther dehiscence started on the second day of flower opening and it proceeded from the outermost whorl to the inner most whorl of the stamens. The dehiscence was hence completed in two days in day bloomers. However, in night bloomers the stamens of all the whorls dehisced simultaneously on the first day of flower opening. The presence of honey dew like secretion in the stigmatic cup indicated the initiation of stigma receptivity in all the accessions irrespective of blooming time. The receptivity started 14 to15 hours before flower opening and was retained for 34 hours even after flower opening in day bloomers. In night bloomers the onset of receptivity was six to nine hours prior to flower opening and remained receptive only for 16 to 18 hours after flower opening. Stingless bee (Trigona irridipennis), honey bee, house flies, weevils and flower beetles were the major insects visiting the flowers. Cross pollination was the rule in all the accessions due to the protogynous nature of the flower. Fruit set was noticed only in two of the day blooming types evaluated. Fruit was a many seeded dehiscent capsule which developed under water. All the floral whorls were persistent in the mature fruit. It took 20 to 25 days for the fruit to mature. Seeds were arillate with an embryo, two fleshy cotyledons and a mucilaginous covering. Despite being a dicot, the germination was initiated by the emergence of coleoptile. Acid scarification as well as leaching treatment enhanced the speed of germination of the seeds. Bulbils served as the propagules in the non seed forming accessions.
Seed dormancy in groundnut
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1992) Presanna Kumari, K T; Narayanan Namboodiri, K M
The present investigation entitled "Seed dormancy in groundnut" was undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1987-1990 using the 419 genotypes received from ICRISAT, Hyderabad. The 419 genotypes possessed varying levels of dormancy at the time of harvest. Genotypes with varying degrees of dormancy were present in all the three botanical groups, viz., hypogaea, fastigiata and vulgaris. The dormancy period of genotypes ranged from 20 to 110 days. The hypogaea genotypes required longer period of rest. The nature of breakage of dormancy and the period of dormancy were found to be two independent phenomena. The factors for dormancy in groundnut were found to be residing in two distinct sites, the cotyledons and the seed coat (testa). Leaching improved the germinability of decoated seeds where as it failed to elicite germination in intact seeds. This indicates that germination inhibitors may be present in the cotyledons and testa retarded the removal of the same. Different genotypes responded differently to various presowing treatments. HgCl2 1, 1000 for five minutes was found to be the best treatment for breaking dormancy. The study of germinability of F1,F2 and F3(embryonic generation) seeds on the day of harvest indicated that dormancy was controlled by polygenes.