Browsing by Author "Bindu, M R"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
ThesisItem Open Access Chromosome behaviour and pollen analysis in anthurium sp(Department of Agricultural Botany, College of Agriculture, Vellayani, 1992) Bindu, M R; KAU; Mercy, S TChromose behaviour and pollen characters had been studied in five commercially important varieties of Anthurium andreanum viz. Honeymoon Red, White (album), Lady Jane (Pink), Chillired and Pink. Some morphological characters were also recorded. The varieties show distinct differences in morphological characters. They can be identified from one another even in the absence of their typical spadices. All the varieties have a somatic chromosome number of 30+2B. The basic chromosome number is x=15. Two B chromosomes are present irrespective of the varietal type. The B chromosomes are either acentric or telocentric and round or rod shaped. Their size is always smaller than the smallest A chromosome. The karyotype of all the five varieties was analysed. On the basis of total chromosome length (TCL), average chromosome length (ACL) and arm ratio (r), the variety Pink appears to be most advanced. When the relative chromosome length (RCL) was taken in to consideration, the variety Chillired is found to be most advanced. With regard to the character, chromosome asymmetry, Lady Jane appears to be most advanced. When the karyotype asymmetry as a whole is considered, all the varieties are falling in the '3B' category which represents a high position in evolution. During meiosis, all the varieties exhibited a wide range of abnormalities like univalent formation, unequal seperation, presence of laggards, micronuclei etc. This point out the hybrid nature of the species. All the varieties are found to be protogynous with distinct interphase. This is an adaptation for natural cross pollination. However, natural crossing is occuring only to a limited extent. The pollen production capacity of the varieties varies significantly. The varieties Honeymoon Red and Pink produce the highest amount of pollen. All the varieties have round pollen with a single germ pore. The pollen size among the varieties does not vary significantly. However, the variety Lady Jane has the largest pollen. Pollen fertility is very low, when it was tested by acetocarmine staining and in vitro pollen germination methods. The latter is found to be more reliable in estimating the pollen fertility. All the varieties have paracytic type of stomata. But the varieties vary widely in their size and distribution. Morphological variations, karyotypic differences, meiotic abnormalities, high pollen sterility and the wide variability in stomatal characters point out the basic hybrid nature of the species.ThesisItem Open Access Genetic diversity analysis of horse gram [Macrotyloma uniflorum (Lam.) Verdc.] for moisture stress tolerance in south central laterites of Kerala(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2022) Visakh, R L; KAU; Bindu, M RThe study entitled “Genetic diversity analysis of horse gram [Macrotyloma uniflorum (Lam.) Verdc.] for moisture stress tolerance in south central laterites of Kerala” was carried out at Farming Systems Research station, Sadanandapuram during October, 2020 – March, 2021 with the objective to identify superior genotypes of horse gram with moisture stress tolerance having high yield and quality, suitable for south central laterites of Kerala. The 30 horse gram genotypes collected from RARS Pattambi under KAU and other SAUs were evaluated for moisture stress tolerance at seedling stage in laboratory using two different concentrations of PEG 6000 (10% and 20%), in factorial completely randomized design replicated thrice. These 30 genotypes were further evaluated for water stress tolerance in field by withholding irrigation for 15 days at reproductive stage, in randomized block design replicated thrice. The seeds were sown on raised beds of 2.25 m2 size at a spacing of 30 cm х 30 cm and cultural operations were adopted as per the “Package of Practices Recommendations Crops 2016” of Kerala Agricultural University. The soil moisture was also measured during water stress-imposed period at weekly interval by following gravimetric method. In laboratory experiment, genotypes were evaluated for six different morphophysiological characters and in field experiment, genotypes were evaluated for 31 characters which included biometric, physiological, biochemical and seed quality characters. The genotypes showed significant differences for all the characters studied. Genetic parameter analysis was performed for nineteen characters and for all the characters PCV values were higher than GCV values indicating the influence of environment. High heritability coupled with high GAM was observed in days to 50% flowering, number of primary branches per plant, plant height, number of pods per plant, haulm yield per plant, harvest index, days to maturity, leaf area index, total phenol content of the seed, root dry weight, proline content, total chlorophyll content and seed yield per plant. 124 The correlation studies revealed significant positive correlation of the characters RWC, number of pods per plant, number of seeds per pod, total chlorophyll content, harvest index, proline content, root dry weight, root length, LAI and hundred seed weight with seed yield. However, days to 50% flowering, days to maturity, plant height and number of primary branches showed a significant negative correlation with yield. Path analysis of the thirteen characters showing significant correlation with seed yield revealed high positive direct effect of the number of pods per plant on seed yield. High indirect effect on yield was observed for number of seeds per pod through number of pods per plant. Genetic divergence analysis using Mahanalobis D2 statistic following Tocher’s method grouped the 30 genotypes into four clusters. Cluster II with 14 genotypes was the largest followed by cluster I (9 genotypes), cluster III (6 genotypes) and clusters IV was solitary cluster. Highest intra cluster distance was recorded among the genotypes of cluster II and lowest in cluster IV whereas highest inter cluster distance was observed between the genotypes of the clusters I and III, while lowest inter cluster distance was between the genotypes of the clusters III and IV. The present study revealed that the genotypes IC71841, IC139464 and IC22785 as water stress tolerant ones in laboratory experiment and in field experiment, genotypes IC22785, IC221105, IC22759 and IC139464 were identified as high yielding and moisture stress tolerant ones. The superior genotypes identified in the study can be recommended for cultivation and future breeding programs.ThesisItem Open Access Genetic variability studies in grain cowpea (Vigna unguiculata (L.) Walp.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2020) Darshana, A S.; KAU; Bindu, M RThe study entitled “Genetic variability studies in grain cowpea (Vigna unguiculata (L.) Walp.) was carried out at Farming Systems Research station, Sadanandapuram during December, 2019 – March, 2020 with the objective to evaluate and select shade tolerant grain cowpea genotypes suited to the coconut based homesteads. The 33 grain cowpea genotypes collected from research stations under KAU, AICRP centre and agricultural universities of different states were evaluated in coconut based homestead garden where coconuts are of age 30 – 40 years, in randomized block design replicated thrice. The seeds were sown on raised beds of (3 х 1.5) m2 size at a spacing of 30 cm х 15 cm and cultural operations and plant protection measures were adopted as per the “Package of Practices Recommendations: Crops 2016” of Kerala Agricultural University. The average light intensity in the experimental field recorded was 0.719 W/m2 resulting in shade of 33.49 per cent. The genotypes were evaluated for biometric and physiological characters associated with shade tolerance and quality character of seed. The genotypes showed significant differences for all the characters studied. Genetic parameter analysis was performed for twelve characters and for all the characters PCV values were higher than GCV values indicating the influence of environment. The phenotypic and genotypic coefficients of variation were maximum for seed yield per plant and minimum for protein content. Heritability was high for all the twelve characters and genetic gain was high for all the characters except days to 50% flowering and protein content. The correlation studies revealed positive correlation of the characters days to 50% flowering, number of pods per plant, number of seeds per pod, crop duration, harvest index, LAD at flowering, CGR at flowering and protein content with seed yield. The path analysis provides information on contribution of traits by partitioning the total correlation into direct and indirect effects. Path analysis of the eight characters showing significant correlation with seed yield revealed high positive direct effect of the characters number of pods per plant and harvest index on seed yield. High indirect effect on seed yield was observed for CGR at flowering through number of pods per plant. Cluster analysis aids in the selection of genetically divergent parents for hybridization programme which results in greater heterosis. Cluster analysis using Mahanalobis D2 statistic following Tocher’s method grouped the 33 genotypes into nine clusters. Cluster II with 10 genotypes was the largest followed by cluster I and cluster V (8 genotypes each), cluster III (2 genotypes) and clusters IV, VI, VII, VIII, IX which were solitary clusters. Highest intra cluster distance was recorded among the genotypes of cluster V and lowest in cluster III whereas highest inter cluster distance was observed between the genotypes of the clusters III and IX followed by clusters VI and IX. The present study revealed that the variety Sreya recorded highest seed yield under partially shaded condition. The genotypes CHESCP-03, CHESCP-17 and CHESCP-32 are medium in duration with shade tolerance and higher yield, hence suited to the coconut based homesteads. Among the early duration types, Subhra recorded the highest yield. Genotypes CHESCP-19 and KYLMVU-6 recorded yield on par with the shade tolerant genotypes CHESCP-03, CHESCP-17 and CHESCP-32. Subhra and the late duration varieties Sreya, CHESCP-19 and KYLMVU-6 recorded low values for shade tolerant parameters and there is scope for improving the yield by hybridization with shade tolerant varieties. Subhra and CHESCP-21 were found to be superior for protein content. As quality of a pulse variety is determined by the protein content, these genotypes can be used as parents in quality improvement programmes. The superior genotypes identified in the study can be recommended for cultivation and future breeding programs.ArticleItem Open Access Pollen studies in anthurium andreanum lin.(Kerala Agricultural University, 1996) Bindu, M R; Mercy, S T; KAUFloral biology and pollen characters of five varieties of Anthurium andreanum Lin. have been studied. It was observed that the species is protogynous. Anthesis occurred during early morning hours. The plant produces a large number of pollen grains per anther which are more or less uniform in size, round in shape with a single germ pore. Only a small percentage of pollen grains is fertile which reflects the hybrid nature of the species. Determination of pollen fertility by in vitro pollen germination method is found to be more accurate than by acetocarmine staining.ThesisItem Open Access Standardisation of in vitro techniques for rooting,hardening and micrografting in cocoa (Theobroma cacao L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1997) Bindu, M R; KAU; Mallika, V KInvestigations on 'Standardisation of in vitro techniques for rooting, hardening and micrografting in cocoa (Theobroma cacao L.)' were carried out at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara utilising the existing facilities of the Plant Tissue Culture Lahoratory of the Department of Plantation Crops and Spices during the period from 1993-1996. Studies were conducted to identify the best rooting protocol and also to refine the technique of micrografting. The nodal segments taken from the field were pretreated with Bavistin (0. 1 %) for half an hour and then surface sterilized in chlorine water for four minutes. The explants were then cultured in the medium, WPM + 2ip 5 + AgNO3 5 + CCC 0.75 + AdSO4 + PG 200 mg l-1 and incubated at 28 + 2oC under 4000 lux light intensity for shoot bud release. For getting sufficient number of elongated shoots, subculturing was done in WPM supplemented with 0.5 % activated charcoal and 200 mg l-1 streptomycin sulphate. Observations of three different genotypes revealed that they responded differently to in vitro contidition and the genotype S 44.1 exhibited a very good growth. Rooting was very poor under In vitro condition and was completely absent under ex vitro condition. Among the different basal media for in vitro rooting, 1/2 MS supplemented with activated charcoal was the best. Maximum rooting was obtained when the shoots were pretreated in IBA 5000 mg l-1 for 3 seconds followed by culturing in the basal medium. Optimum concentration of sucrose for rooting was 3 per cent and that of agar was 0.6 per cent. For rooting, the cultures should be kept at a temperature of 28 + 20 C under dark condition. The genotypes differed in their response to rooting. Among the three genotypes - S 44.1, G VI 67 and G IV 4.1 tested, S 44.1 recorded better rooting. The rooted shoots should be potted in a medium containing a mixture of soilrite and potting mixture in equal proportion for establishment. The plantlets should be covered with polybags for 2-3 weeks and then exposed to ambient condi- tions periodically for hardening. Plantlet survival rate decreased up to the second month of planting out and after that it became static. In vitro micrografting and ex vito micrografting were possible in cocoa. The best rootstock for in vitro micrografting was axenic seedlings cultured in half MS liquid medium devoid of sucrose. These seedlings were ready for grafting in two weeks when raised under high light intensity (4000 lux) and high temperature (28 + 2°C). In vitro shoots from nodal segments were found to be a very good scion material for grafting. Among the different grafting techniqes, side grafting was the most ideal one. Success was the highest when scions with two or more hardened leaves were grafted 4 cm below the cotyledons in 4-5 weeks old axenic seedlings. Anatomical studies revealed that the graft union was complete in about a month. Grafted seedlings showed profuse growth after planting out. Ex vitro micrografting recorded lower percentage of success than in vitro micrografting. Older plants with a few hardened leaves were the most ideal root- stock and the scions should have at least one hardened leaf. Rapid and extensive scion elongation was observed in ex vitro micrografting. The most significant achievement of the present investigation was the standardisation of the technique of in vitro micrografting by which the rooting problem can be surmounted to a great extent.