Browsing by Author "Bindu, M R"

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Chromosome behaviour and pollen analysis in anthurium sp
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1992) Bindu, M R; Mercy, S T
Chromose 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.
Development and evaluation of high yielding, mosaic tolerant backcross progenies in bitter gourd (Momordica charantia L.) variety Preethi using morphological, biochemical and molecular markers
(Department of Genetics and Plant Breeding, College of Agriculture ,Vellayani, 2024-05-23) Ankitha, M O; KAU; Bindu, M R
The present research work entitled ‘Development and evaluation of high yielding, mosaic tolerant backcross progenies in bitter gourd (Momordica charantia L.) variety Preethi using morphological, biochemical and molecular markers’ was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani and Farming Systems Research Station (FSRS), Sadanandapuram during the year 2020-2023, with an objective to develop high yielding mosaic tolerant backcross progenies in bitter gourd using morphological, biochemical and molecular markers. Thirty three bitter gourd genotypes, including KAU released varieties (2 No’s), NBPGR accessions (13 No’s), and local collections from all over India were used for screening mosaic tolerance. Out of the 33 genotypes, 26 genotypes were Momordica charantia var. charantia and seven were Momordica charantia var. muricata. All these genotypes were artificially inoculated with the three viruses Cucumber Mosaic Virus (CMV), Tomato Leaf Curl New Delhi Virus (ToLCNDV) and Papaya Ringspot virus (PRSV) through wedge grafting. Wedge grafting was done using the infected plant shoots as scion and the collected genotypes as root stock and regrowth from the cotyledonary axis was examined for symptom expression. Out of the 33 genotypes screened, three were highly resistant, four were resistant, five were moderately resistant, six were moderately susceptible, ten were susceptible and five were highly susceptible. The genotypes Lodhi local, Udayagiri local and Therthali local recorded a lowest Vulnerability Index of zero. Molecular markers reported in Cucurbitaceae family were validated for bitter gourd mosaic resistance gene. SSR-11-1 marker for CMV resistance and CAPS marker for Potyvirus resistance gene were used, but no amplification was obtained. Double Antibody Sandwich ELISA (DAS-ELISA) was performed to confirm the resistance reaction of three highly resistant genotypes identified in seedling screening. Optical density (OD) value of the genotypes for the three viruses, CMV, ToLCNDV and PRSV were less than twice the OD value of the un-inoculated healthy plant which confirmed highly resistant disease reaction of genotypes. Molecular confirmation was done by using coat protein primer (Deng primer) specific to the Begomovirus group. Deng primer amplifies coat protein gene of ToLCNDV (520 bp), so that band will be present in only susceptible genotypes and will be absent in resistant ones. Plant defense related enzymes such as peroxidase, polyphenol oxidase and phenyl alanine ammonialyase was estimated and there was increased rate of synthesis of these enzymes in the identified resistant genotypes. So the identified resistant genotypes, Lodhi local, Udayagiri local and Therthali local were used as the donor parent for imparting mosaic resistance into the bitter gourd variety Preethi. Lodhi local is M. charantia var. charantia genotype where as both Udayagiri local and Therthali local are M. charantia var. muricata genotypes. High yielding variety released from KAU viz., ‘Preethi’ was selected as the recurrent parent in the study. Preethi was crossed with the three donor parents and F1s were produced. The F1s were morphologically evaluated with the parents for seventeen characters and it was observed that all the characters of F1 were approximately the average of two parents. All the F1s were backcrossed with Preethi to produce BC1F1 segregants. In the backcross progeny of the cross involving Preethi and Lodhi local, a total of 176 BC1F1 lines were developed. BC1F1 lines were artificially inoculated for their disease reaction. Among the 176 BC1F1 lines, 22 were found to be highly resistant to mosaic disease, 30 were resistant, 30 were moderately resistant, 26 were moderately susceptible, 35 were susceptible and 33 were highly susceptible. Confirmation of resistance was done using DAS- ELISA, Deng primers and estimation of defense enzymes. All the 17 biometrical characters were recorded and the Euclidean distance of the highly resistant BC1F1 lines from the recurrent parent Preethi was calculated using proximity dissimilarity matrix analysis. The 14 BC1F1 lines with high phenotypic similarity to Preethi was backcrossed to develop BC2F1 lines. In the backcross progeny of the cross involving Preethi and Udayagiri local, a total of 170 BC1F1 lines were produced. Among them 15 BC1F1 lines were highly resistant. Resistant reaction of identified 15 BC1F1 was confirmed by DAS-ELISA, molecular screening and biochemical analysis. Euclidean distance of the highly resistant 15 BC1F1 lines from the recurrent parent revealed that eight lines showed similarity with Preethi and they were backcrossed to get BC2F1 lines. A total 147 BC1F1 lines of the cross involving Preethi and Therthali local were screened at seedling stage. Out of the 147 lines, 16 BC1F1 lines were highly resistant. DAS-ELISA, molecular screening using aforementioned Deng primer confirmed the resistant reaction of these lines. Euclidean distance using biometric characters found that, out of 16 highly resistant BC1F1 lines eight lines had close proximity with Preethi. These lines were used to produce BC2F1 lines. The 190 BC2F1 lines of the cross involving Preethi and Lodhi local were screened at seedling stage and in 24 BC2F1 lines, there was absence of virus coat protein band which confirmed the highly resistant disease reaction of the aforementioned lines. The 12 BC2F1 lines with the shortest Euclidean distance and high phenotypic similarity with Preethi were selfed to generate BC2F2 seeds. In the 134 BC2F1 lines of the cross involving Preethi and Udayairi local, seedling screening recorded 17 highly resistant lines. After molecular confirmation of mosaic resistance four BC2F1 lines with close proximity to Preethi were selfed to get BC2F2 seeds. Out of the 143 BC2F1 lines of the cross involving Preethi and Therthali local, 20 BC2F1 lines were highly resistant. The molecular analysis of the 20 BC2F1 lines also confirmed the highly resistant reaction. Four BC2F1 lines with the shortest Euclidean distance was selected and selfed to produce BC2F2 seeds. Although there were BC2F2 seeds of three different crosses, only the BC2F2 seeds of the cross involving Preethi and Lodhi local was carried forward for further backcrossing. This is due to the low yield potential of the backcross progenies of the crosses involving M. charantia var. muricata genotypes. So 206 BC2F2 lines of the cross involving Preethi and Lodhi local were artificially screened at seedling stage for mosaic incidence. Out of the 206 BC2F2 lines, 42 plants were highly resistant to bitter gourd mosaic viruses. The 42 mosaic tolerant backcross inbred lines developed in the study can be carried forward for the development of a mosaic tolerant essentially derived variety (EDV) in the background of high yielding variety Preethi. The backcross progenies obtained in the crosses involving muricata genotypes can be further evaluated for its nutraceutical values.
Development and evaluation of high yielding, mosaic tolerant backcross progenies in bitter gourd (Momordica charantia L.) variety Preethi using morphological, biochemical and molecular markers
(Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, 2024-05-23) Ankitha, M O; KAU; Bindu, M R
The present research work entitled ‘Development and evaluation of high yielding, mosaic tolerant backcross progenies in bitter gourd (Momordica charantia L.) variety Preethi using morphological, biochemical and molecular markers’ was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani and Farming Systems Research Station (FSRS), Sadanandapuram during the year 2020-2023, with an objective to develop high yielding mosaic tolerant backcross progenies in bitter gourd using morphological, biochemical and molecular markers. Thirty three bitter gourd genotypes, including KAU released varieties (2 No’s), NBPGR accessions (13 No’s), and local collections from all over India were used for screening mosaic tolerance. Out of the 33 genotypes, 26 genotypes were Momordica charantia var. charantia and seven were Momordica charantia var. muricata. All these genotypes were artificially inoculated with the three viruses Cucumber Mosaic Virus (CMV), Tomato Leaf Curl New Delhi Virus (ToLCNDV) and Papaya Ringspot virus (PRSV) through wedge grafting. Wedge grafting was done using the infected plant shoots as scion and the collected genotypes as root stock and regrowth from the cotyledonary axis was examined for symptom expression. Out of the 33 genotypes screened, three were highly resistant, four were resistant, five were moderately resistant, six were moderately susceptible, ten were susceptible and five were highly susceptible. The genotypes Lodhi local, Udayagiri local and Therthali local recorded a lowest Vulnerability Index of zero. Molecular markers reported in Cucurbitaceae family were validated for bitter gourd mosaic resistance gene. SSR-11-1 marker for CMV resistance and CAPS marker for Potyvirus resistance gene were used, but no amplification was obtained. Double Antibody Sandwich ELISA (DAS-ELISA) was performed to confirm the resistance reaction of three highly resistant genotypes identified in seedling screening. Optical density (OD) value of the genotypes for the three viruses, CMV, ToLCNDV and PRSV were less than twice the OD value of the un-inoculated healthy plant which confirmed highly resistant disease reaction of genotypes. Molecular confirmation was done by using coat protein primer (Deng primer) specific to the Begomovirus group. Deng primer amplifies coat protein gene of ToLCNDV (520 bp), so that band will be present in only susceptible genotypes and will be absent in resistant ones. Plant defense related enzymes such as peroxidase, polyphenol oxidase and phenyl alanine ammonialyase was estimated and there was increased rate of synthesis of these enzymes in the identified resistant genotypes. So the identified resistant genotypes, Lodhi local, Udayagiri local and Therthali local were used as the donor parent for imparting mosaic resistance into the bitter gourd variety Preethi. Lodhi local is M. charantia var. charantia genotype where as both Udayagiri local and Therthali local are M. charantia var. muricata genotypes. High yielding variety released from KAU viz., ‘Preethi’ was selected as the recurrent parent in the study. Preethi was crossed with the three donor parents and F1s were produced. The F1s were morphologically evaluated with the parents for seventeen characters and it was observed that all the characters of F1 were approximately the average of two parents. All the F1s were backcrossed with Preethi to produce BC1F1 segregants. In the backcross progeny of the cross involving Preethi and Lodhi local, a total of 176 BC1F1 lines were developed. BC1F1 lines were artificially inoculated for their disease reaction. Among the 176 BC1F1 lines, 22 were found to be highly resistant to mosaic disease, 30 were resistant, 30 were moderately resistant, 26 were moderately susceptible, 35 were susceptible and 33 were highly susceptible. Confirmation of resistance was done using DAS- ELISA, Deng primers and estimation of defense enzymes. All the 17 biometrical characters were recorded and the Euclidean distance of the highly resistant BC1F1 lines from the recurrent parent Preethi was calculated using proximity dissimilarity matrix analysis. The 14 BC1F1 lines with high phenotypic similarity to Preethi was backcrossed to develop BC2F1 lines. In the backcross progeny of the cross involving Preethi and Udayagiri local, a total of 170 BC1F1 lines were produced. Among them 15 BC1F1 lines were highly resistant. Resistant reaction of identified 15 BC1F1 was confirmed by DAS-ELISA, molecular screening and biochemical analysis. Euclidean distance of the highly resistant 15 BC1F1 lines from the recurrent parent revealed that eight lines showed similarity with Preethi and they were backcrossed to get BC2F1 lines. A total 147 BC1F1 lines of the cross involving Preethi and Therthali local were screened at seedling stage. Out of the 147 lines, 16 BC1F1 lines were highly resistant. DAS-ELISA, molecular screening using aforementioned Deng primer confirmed the resistant reaction of these lines. Euclidean distance using biometric characters found that, out of 16 highly resistant BC1F1 lines eight lines had close proximity with Preethi. These lines were used to produce BC2F1 lines. The 190 BC2F1 lines of the cross involving Preethi and Lodhi local were screened at seedling stage and in 24 BC2F1 lines, there was absence of virus coat protein band which confirmed the highly resistant disease reaction of the aforementioned lines. The 12 BC2F1 lines with the shortest Euclidean distance and high phenotypic similarity with Preethi were selfed to generate BC2F2 seeds. In the 134 BC2F1 lines of the cross involving Preethi and Udayairi local, seedling screening recorded 17 highly resistant lines. After molecular confirmation of mosaic resistance four BC2F1 lines with close proximity to Preethi were selfed to get BC2F2 seeds. Out of the 143 BC2F1 lines of the cross involving Preethi and Therthali local, 20 BC2F1 lines were highly resistant. The molecular analysis of the 20 BC2F1 lines also confirmed the highly resistant reaction. Four BC2F1 lines with the shortest Euclidean distance was selected and selfed to produce BC2F2 seeds. Although there were BC2F2 seeds of three different crosses, only the BC2F2 seeds of the cross involving Preethi and Lodhi local was carried forward for further backcrossing. This is due to the low yield potential of the backcross progenies of the crosses involving M. charantia var. muricata genotypes. So 206 BC2F2 lines of the cross involving Preethi and Lodhi local were artificially screened at seedling stage for mosaic incidence. Out of the 206 BC2F2 lines, 42 plants were highly resistant to bitter gourd mosaic viruses. The 42 mosaic tolerant backcross inbred lines developed in the study can be carried forward for the development of a mosaic tolerant essentially derived variety (EDV) in the background of high yielding variety Preethi. The backcross progenies obtained in the crosses involving muricata genotypes can be further evaluated for its nutraceutical values.
Genetic analysis of medium duration rice genotypes for tolerance to iron toxicity in south central laterites of Kerala
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2022-01-22) Anandhu Raj; Bindu, M R
The present study entitled “Genetic analysis of medium duration rice genotypes for tolerance to iron toxicity in South Central Laterites of Kerala” was conducted at Farming Systems Research Station, Sadanandapuram to evaluate and select rice genotypes tolerant to iron toxicity suited to South Central Laterites of Kerala during 2019-2021. The project was implemented as two experiments and in Experiment-I, initial evaluation of rice genotypes for iron toxicity tolerance was done as pot culture study. In Experiment-II, genotypes selected from experiment-1 was evaluated in paddy field where soil iron is at a toxic level. Thirty rice genotypes were collected from different research stations under KAU. Growing media consist of washed sand in polybags kept in plastic basins filled with Hoagland solution at different concentration (0,200,400,600 mgl-1) of iron at a constant pH of 4.0. Rice genotypes Uma, Karishma, Thekkan chitteni, Pournami, Panchami, Gouri, Bharati, Aiswarya, Asha, Pavithra and Samyuktha were selected from 30 genotypes screened in the laboratory based on morphological characters and iron toxicity score at highest iron concentration (600 mgl-1). Eleven rice genotypes were evaluated in field in iron toxicity affected field with pH (4.9) and iron content (544 mg kg-1), in randomized block design. Germinated seeds were sown in nursery and 21 days old seedlings were transplanted to main field. Seedlings were transplanted at a spacing of 20cm X 15cm. Agronomic practices which include lime application (600 kg ha-1) were carried out according to “Package of Practices Recommendation Crops 2016” of Kerala Agricultural University (KAU, 2016). A control block without lime application containing all treatments were maintained. The genotypes were evaluated for 33 characters including biometric and biochemical characters associated with iron toxicity tolerance. The genotypes showed significant differences for all the characters studied. Genetic parameter analysis was performed for 21 characters and for all the characters PCV values were higher than GCV values indicating the influence of environment. The phenotypic and genotypic coefficient of variation were maximum for straw yield per plant and minimum for days to 50% flowering. High heritability coupled with high genetic advance was observed for plant height, total number of tillers per plant, number of productive tillers per plant, panicle weight, sterility percentage, root length, grain yield per plant, straw yield per plant, number of fresh roots (20 DAT), iron content on root, iron content on 3rd leaf from tip, iron content in oldest fully opened matured leaf, iron content in grain, iron content in straw. Days to 50% flowering, number of tillers per plant, number of productive tillers per plant, panicle length, panicle weight, number of grains per panicle, number of filled grains per panicle, 1000 grain weight, root length and total number of roots (20 DAT) showed positive correlation with grain yield per plant. The path analysis provides information on contribution of traits by partitioning the total correlation into direct and indirect effects. Path analysis revealed highest positive direct effect of days to 50% flowering on grain yield per plant. Highest indirect effect of number of grains per panicle through days to 50% flowering. 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 11 genotypes into five clusters.Cluster I with 7 genotypes was the largest and cluster II, III, IV, V were solitary. Intra cluster distance was recorded only in cluster I (11.32). Highest intercluster distance observed between genotypes of cluster V and cluster II. The present study revealed that genotypes Panchami (6.4 t/ha) recorded maximum yield and was followed by Pournami (5.7 t/ha). These varieties can be recommended for iron toxic low land paddy fields of South Central Laterites of Kerala. Genotypes Panchami, Pournami, Uma, Karishma, Gouri and Pavithra recorded lowest leaf bronzing score at maturity under iron toxic field conditions. These genotypes can be used in breeding programmes to develop iron toxicity tolerant rice varieties.
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; Bindu, M R
The 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.
Genetic variability studies in grain cowpea (Vigna unguiculata (L.) Walp.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2020) Darshana, A S; Bindu, M R
Identification of superior genotypes for water stress tolerance in rice (Oryza sativa L.) for south central laterites of Kerala
(Department of Plant Breeding and Genetics, College of Agriculture,Vellayani, 2022-02-18) Aravind Krishna; Bindu, M R
He present investigation entitled “Identification of superior genotypes for water stress tolerance in rice (Oryza sativa L.) for south central laterites of Kerala” was conducted at Farming Systems Research Station, Sadanandapuram, Kottarakkara during 2019-21 with an objective to identify and characterize the traditional as well as released rice genotypes of Kerala for water stress tolerance using phenotypic and biochemical markers, suitable for south central laterites of Kerala. The study comprised of thirty genotypes collected from RARS, Pattambi, Department of Seed Science and Technology, College of Agriculture, Vellanikkara, KAU, Thrissur and ICAR- NBPGR, New Delhi. Study was conducted in two experiments viz. laboratory and field study. In the first experiment (Experiment-I), thirty genotypes were evaluated for moisture stress tolerance at seedling stage for seven different morpho-physiological characters viz. Germination percentage, speed of germination, root length, shoot length, seedling dry weight, seedling vigor index 1 and seedling vigor index 2 in laboratory using PEG 6000 (Polyethylene Glycol- 6000) at five different concentrations of 0, 5, 10, 15, 20 percentage (%). The study was conducted in factorial completely randomized design, replicated thrice and the twenty-one tolerant genotypes were selected for field study. In the second experiment (Experiment-II), twenty-one best performing genotypes including the high performing standard check variety Apo in randomized block design were selected and evaluated in the field where irrigation was withheld for 10 days at critical growth stages. The seeds were sown on raised beds of 4 m2 size at a spacing of 20 cm х 20 cm and cultural operations were adopted as per the “Package of Practices (2016)” of Kerala Agricultural University. Genotypes were evaluated for twenty-four characters which included different biometric, physiological and biochemical observations. Significant difference was observed among genotypes for all the characters studied in both field and laboratory experiments. Genetic parameter analysis was performed for 21 characters and for all the characters PCV values were higher than GCV values indicating the influence of environment. The phenotypic and genotypic coefficient of variation were maximum for recovery after stress release and minimum for days to 50 % flowering. Heritability was high for all the characters except leaf rolling score and genetic gain was high for all the selected characters. Correlation studies revealed significant positive correlation for all the selected characters except spikelet sterility, which exhibited significant negative correlation with grain yield. Path analysis conducted for eleven characters showed significant correlation with grain yield and also revealed that relative water content recorded high positive direct effect on grain yield. High positive indirect effect on grain yield was recorded by grain weight per panicle via spikelet sterility. Genetic
Pollen studies in Anthurium andreanum Lin.
(Kerala Agricultural University, 1996) Bindu, M R; Mercy, S T
Floral 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
Pollen studies in anthurium andreanum lin.
(Kerala Agricultural University, 1996) Bindu, M R; Mercy, S T
Floral 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.
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; Mallika, V K