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Open Access
Androgenesis in rice (Oryza sativa L.) breeding
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2004) Chandrahasan, V T; KAU; Dijee Bastian
An investigation was carried out in rice, at the College of Horticulture, Vellanikkara to produce doubled haploid lines through anther culture technique. The study included production of a hybrid between IR 36 (ovule parent) and PTB 45 (pollen parent), evaluation of parents and hybrid, culturing the anthers of F1 to produce doubled haploids and analyse the effect of growth regulators (2,4-D, Kn, IAA and IBA) and carbon source (sucrose and maltose) on callus induction. There was significant difference among the parents and hybrid. The hybrid recorded significantly different values for plant height, panicle length, grains / panicle, grain weight and grain yield / plant. Among the 24 treatments used for anther culture, callus induction was observed in 11 treatments. Callus induction percentage ranged from 0 to 4.18. Maximum callus induction percentage was recorded in N6 medium supplemented with maltose 60 mg/l, 2, 4-D 2mg/l and Kn 0.5 mg/l (4.18%) followed by N6 medium supplemented with maltose 60 mg/l, 2, 4-D 2 mg/l and Kn 1mg/l (3.32%). A significant increase in anther culture efficiency was observed when sucrose was replaced by maltose in the presence of growth regulators 2,4-D/Kn but not in the presence of IAA/Kn. Callus induction frequency was high in 2,4-D/Kn combination followed by IAA/Kn combination irrespective of carbon source. IBA/Kn combination was totally non-responsive. Main effects of 2, 4-D and Kn were significant, but there was no interaction between 2, 4-D and Kn when sucrose was used as carbon source. Among the two levels of 2, 4-D, 3 mg/l (0.6%) was superior to 2 mg/l (0.24%) and among the two levels of kinetin 0.5 mg/l (0.71%) was superior to 1 mg/l (0.12%). Main effects of 2, 4-D only was significant when maltose was used as carbon source. Main effect of 2, 4-D indicated that there was significant reduction in callus induction response when level of 2, 4-D increased from 2mg/l (3.75%) to 3mg/l (2.31%). Sixty six calli were obtained through anther culture of which 57 were embryogenic calli and the rest non-embryogenic calli. The percentage of embryogenic calli (86.45%) was higher than non-embryogenic calli (13.6%). 2, 4-D/Kn combination produced more number of embryogenic calli (88.3%) than IAA/Kn combination (66.7%). Thirty green plants and five albinos were obtained from regeneration medium. The frequency of green plant and the albinos were 85.71 per cent and 14.29 per cent respectively. Regeneration frequency of embryogenic and non-embyogenic calli were 27.19 per cent and 22.22 per cent respectively. Among 30 green plants obtained , 21 were homozygous diploids and the rest haploids. Frequency of spontaneous doubling was 70 per cent. Of the 30 regenerated plants taken for hardening 24 survived and all were observed for grains per panicle and seed setting percentage. The values of grains per panicle and seed setting percentage ranged from 87 to 106 and 89.79 to 95.33 respectively.
Open Access
Molecular documentation of njavara types of rice (Oryza sativa L.) for cultivar identification
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2007) Shareesh, N; KAU; Elsy, C R
Characterisation and evaluation of Njavara types of rice (Oryza sativa L.) was under taken in the Department of Plant Breeding and Genetics and Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during 2005 - 2007 with the objective of molecular characterization and gene sequencing in Njavara for developing suitable molecular markers for cultivar identification. Njavara genotypes exhibited high variability with respect to lemma and palea colour with two major classes viz., yellow (straw colour) and black types. Detailed characterization revealed that yellow type could be further grouped into gold furrows on straw (N3 & N5) and brown furrows on straw (N4 & N7). Three genotypes viz., N1, N2 and N6 exhibited a lemma and palea colour dominated by black. N1 and N2 exhibited variations in black colour for lemma and palea as pure black, black furrows/black patches on straw background whereas N6 exhibited light shade of black. Variations in seed coat colour as red, light brown and brown were also observed among the genotypes. The method suggested by Dellaporta et al. (1983) with slight modifications was found to be effective in isolating good quality genomic DNA from Njavara. Good amplifications were observed when RAPD analysis was performed with sequences OPA 1, OPA 4, OPA 6, OPA7 , OPA 9, OPN 6, OPN 18, OPP 6, OPP 11 and OPE 6. OPA 1 and OPP 11 were found to be promising in the amplification of rice genomic DNA with maximum amplification. Amplification of Njavara DNA with primer OPE 6 exhibited unique bands (1.375 kb , 1.29 kb and 0.44 kb ) for Njavara genotypes and hence are valuable as DNA markers for the identification of this unique cultivar. The dendrogram with RAPD markers showed distinct clusters for Njavara. Cloning and sequencing of the unique molecular band with M 13 primer gave the sequence data of a gene segment of size 762 bp.The homology search of this sequence with BLASTN showed that it has maximum identity with genes from Oryza sativa (japonica cultivar-group) mitochondrial gene for tRNA-Asn, complete sequence, O. sativa mRNA for chilling-inducible protein, O.sativa rbbi2-5 gene for putative Bowman Birk tryspin inhibitor, O.sativa rbbi2-3 gene for putative Bowman Birk trypsin inhibitor, O.sativa rbbi2-4 gene for putative Bowman Birk trypsin inhibitor and O. sativa (japonica cultivar-group) mRNA for chilling tolerance related protein.The homology of cloned DNA fragments of Njavara (N5) with BBI genes (rbbi 2-3, rbbi 2-4 and rbbi 2-5 ) is a preliminary indication of the medicinal property (anticarcinogenic) of this unique medicinal cultivar of Kerala and also its thermostable nature. Sequence analysis revealed the presence of five ORF’s . The longest open reading frame had 180 bases encoding 59 amino acids in the predicted coding region. Among the amino acids, serine was occurring more frequently than other amino acids. ORF in +3 reading frame was found to be of a residue length of 102 bases, encoding 33 amino acids. Genscan tool determined two internal exons from the clone with a length of 91 and 129 residues. Sequence analysis of the data with VecScreen showed strong match to vector sequences in the database eventhough the sequences were not matching with pSCA (vector used in the present study) vector. Alignment of sequences through CLUSTAL W programme revealed poor homology with query sequence and vector sequence used for cloning. Homology was shown between the sequences when BLAST 2 SEQUENCES programme was used. These results are to be confirmed through further studies.
Open Access
Evaluation of microsatellite markers for selection of crossbred cattle
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2005) Naicy, Thomas; KAU; Anilkumar, K
The possibility of using the informations of the allele frequency, genotype frequency, heterozygosity and PIC of five selected microsatellite markers (ILSTS096, HUJII77, BL41, BM1508 and BM4305) and their associations with the economically important traits for the selection of crossbred cattle were studied. Among the economic traits studied milk fat percentage and AFC showed significant difference among the ten sire families and hence their associations with the selected microsatellite markers were worked out. PCR conditions were standardised for each marker separately. The number of alleles, size range and number of genotypes identified were 12, 188-212 bp and 35 respectively for ILSTS096 locus, 13, 193-221 bp and 36 for HUJII77 locus, 14, 232-266 bp and 36 for BL41 locus, 7, 103-115 bp and 17 at BM1508 locus and 12, 146-168 bp and 37 for BM4305 locus in the unrelated crossbred dairy cattle population. The highest direct count heterozygosity was obtained for ILSTS096 followed by BL41, BM4305, HUJII77 and BM1508 (0.877-0.683). The highest unbiased heterozygosity was obtained for ILSTS096 followed by BL41, BM4305, HUJII77 and BM1508 (0.880-0.686). All the markers were highly informative as their PIC values (0.865-0.630) were more than 0.5. Three sire families namely, Deva, Bull No.250 and Hakkim showed significantly lower milk fat percentage and three other (Dipesh, Onkar and Gopal), showed significantly higher AFC. All the five microsatellite markers had significant effect on milk fat percentage and three of them (ILSTS096, BL41 and BM4305) showed significant effect on AFC. The allelic averages of fat percentage for the allele 188 and 204 at ILSTS096 locus, 205 at HUJII77 locus and 154 at BM4305 locus were significantly lower and that of 198 at ILSTS096 locus, 240 at BL41 locus, 109 and 113 at BM1508 locus and 166 at BM4305 locus were significantly higher. The allelic averages of AFC for the alleles 196 at ILSTS096 locus, 246 at BL41 locus and 154 at BM4305 locus were significantly lower. All these three alleles were absent in the sires of the three families having higher AFC. The allelic frequencies of 188 and 204 of the marker ILSTS096 were low in the population and that of 198 was high. So selection against the alleles 188 and 204 and selection for the allele 198 can be done, but the impact of selection will be meagre. At the BL41 locus, frequency of the allele 240 was comparatively low and the frequency of the allele 242 is very high in the population. So the selection for the allele 240 and selection against the allele 242 will have good impact on milk fat percentage of the selected animals. Frequency of allele 246 in the population is comparatively low. Hence selection for this allele will be favourable to reduce the AFC. The frequency of the allele 109 of BM1508 is low. So selection for this allele will be more beneficial. The animals with the allele 166 at BM4305 locus had the highest average of milk fat percentage and the frequency of this allele in the population is very low, hence selection for this allele will have good impact on higher milk fat percentage.
Open Access
Inheritance of resistance to leaf hopper [Amrasca biguttula biguttula (Ishida)] in okra, Abelmoschus esculentus (L.) Moench.
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Deepthi, Sivanandan; KAU; Sunny, K Ommen
Okra is an important vegetable crop grown in India and abroad for its fresh green pods. The leafhopper Amrasca biguttula biguttula is a major sucking pest of okra causing high damage to plants. High frequency of fruit picking and repeated application of chemical pesticides to tackle the hopper menace, often leaves toxic residues in the fruits. So it is inevitable that pest resistant varieties should be developed. Hence a study was undertaken to study the genetic variability, for yield and its component characters as well leafhopper resistance indices in a collection of okra genotypes, to estimate the combining ability and heterosis as well as gene effects involved in the inheritance of these characters using line x tester analysis. Forty okra germplasms collected from vanous sources were evaluated simultaneously for yield and leaf hopper resistance. ANOV A revealed that the treatments varied significantly for leafhopper resistance and also there was significant variation among treatments for yield and yield attributes viz., days to first flowering, leaf axil bearing first flower, number of primary branches, number of fruits per plant, length of fruit, girth of fruit, weight of fruit, yield per plant duration. Six genotypes exhibited resistance to the leafhopper throughout the crop duration. High values for phenotypic and genotypic coefficients of variation was recorded for number of primary branches followed by leafhopper population count. High heritability was exhibited by yield per plant followed by duration. Maximum genetic advance was observed for number of primary branches followed by yield per plant. Correlation analysis indicated that most character combinations had higher genotypic correlation coefficient than phenotypic correlation coefficient. Yield exhibited significant and positive correlation with number of fruits and average fruit weight and negative significant association with leaf axil bearing first flower, leafhopper population count and leafhopper injury score. Path analysis was carried out for nine biometric as well as two leafhopper injury indices which had high correlation with yield. Highest positive direct effect was exhibited by number of fruits while the highest negative direct effect on yield was recorded for leafhopper population count per plant. Resistant as well as susceptible genotypes were selected based on leafhopper population counts and leafhopper injury score. Five resistant lines (female parent) viz., Nemom (T21), re 45792, Venjaramood (T23), AE 279 and Palappur (T20) and three susceptible testers (male parent) viz., Venganoor (T1S), Aruna (T37) and Kalliyur (T24) were selected as parents for L x T analysis. These were crossed in a line x tester fashion to produce 15 hybrids. During L x T programme highly significant sea as well as gea effects were obtained for yield. Lt was the best line while T 2 was the best tester. Among hybrids L3 x T 2 was the best considering leafhopper resistance as well as yield and yield attributes. Negative and significant sea effects were observed for days to first flowering and leafhopper population count. It possessed all the desirable characters like high yield, greater weight and girth of fruits and number of fruits. It is also an early flowering type. The ratio of additive to dominance variance was less than one for most of the traits studied including leafhopper population counts and leafhopper injury , scores, indicates the predominance of non-additive gene action. Since there is preponderance of non additive gene effects for characters such as yield and its components as well as leafhopper resistance parameters, exploitation of hybrid vigour is an appropriate breeding approach where yield and leafhopper resistance are considered.
Open Access
Compatibility studies in monopodial orchids
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Ninitha Nath, C; KAU; Lekha Rani C
A research programme "Compatibility studies In monopodia! orchids" was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2001-2003 with the objective of undertaking intra and intergeneric hybridization and in vitro embryo culture in monopodial orchids. Twelve monopodial orchid genotypes comprising of six mono generic and six bigeneric hybrids were selected as parents after initial evaluation. They were evaluated adopting completely randomized design with six replications. Analysis of variance revealed significant differences for almost all the characters studied. Genotypic and phenotypic coefficients of variation were high for number of aerial roots, leaf area and width of leaf. Characters like number of aerial roots, width of leaf, leaf area and number of flowers per inflorescence had high heritability coupled with high genetic advance. Significant positive inter-correlation at genotypic and phenotypic levels was observed for length of flow'er and width of flower with number of leaves per cane, number of aerial roots, number of spikes per cane, length of inflorescence and length of scape. The 12 parental genotypes were crossed in all possible combinations (144) after preliminary studies on floral biology. A total of 116 crosses were done including 50 crosses, 54 reciprocals and 12 selfs. Incompatibility reaction was noticed at different stages ranging from flower abscission before the onset of any visible post pollination change to instances where seeds geminated but aborted in culture. A total of 58 combinations attempted succumbed to incompatibility at these different stages from pollination to deflasking. Harvestable green capsules were obtained from 58 combinations and they were inoculated in MS half strength basal medium. Percentage capsule yield ranged from 8 to 38 in the various hybrid combinations. Percentage filled seeds ranged from 18 to 76 in the various combinations. Capsules from twelve combinations did not contain seeds and seeds from ten combinations did not germinate on inoculation. Protocorms of developing seedlings from twelve combinations aborted at various stages of in vitro development. The remaining 24 cross combinations were taken through three to four subculture passages. Seedlings having 2-3 leaves and 2-4 roots were deflasked. Significant differences among the combinations were observed with respect to number of days taken for germination initiation, number of days taken for development of protocorms, chlorophyll, first leaf and first root primordia and for deflasking. Significant differences in seedling morphology were observed among the 24 hybrid combinations at deflasking with respect to all the seven vegetative characters studied.
Open Access
Genetic variability and character associations in Anthurium andreanum Linden
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2002) Asish, K Binodh; KAU; Mayadevi, P
Genetic variability studies was conducted on fifty different genotypes of Anthurium andreanum Linden, generated from a previous hybridisation programme in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. The analysis of variance revealed significant variation among the fifty genotypes for all the seventeen quantitative characters studied. This reveals the high genetic potential for the improvement of this crop. Variability studies indicated that high phenotypic and genotypic coefficients of variation for the characters of total anthocyanin content, pollen fertility, inclination of candle to spathe and duration of interphase. Except for leaf area and number of flowers per candle, all the other characters were highly influenced by genotypic variation. High heritability with a good genetic advance was found for all characters except for suckering ability and number of spadices/plant/year which exhibited medium heritability and high genetic advance. These results indicated that selection of plants which were phenotypically superior with respect to fifteen of the characters studied will certainly result in a significant improvement in the next generations. Plant height was found to have significant positive phenotypic correlation with internode length, leaf area and days from emergence to maturity of inflorescence. Candle length showed significant positive correlation with leaf area, number of flowers per candle, life of spadix and duration of female phase. Genotypic correlations were higher and for most of the characters it showed high positive correlations. Most of the estimates of the environmental correlation coefficients for the characters are low and insignificant indicating the least effect of environment in the expression of the characters studied. Pollen fertility ranged from 7.03 per cent in PR X FR(2) to 50.80 per cent in U X MW. The protogynous nature of the flower and low pollen fertility suggests the hybrid nature of the crop. During the months from March to July, the pollen emergence pattern was less where the maximum and minimum temperatures were relatively high. Path coefficient analysis revealed that the characters leaf area and duration of female phase are more associated with number of flowers per candle and 40 per cent variation in flower production was attributed by the environment. High selection index values were recorded by the genotype LR X DT followed by FR X MW(l), PR X LR (3), MW X FRO). If parents are selected based on selection index values, 45 per cent genetic gain can be expected in the next generation.
Open Access
Impact of seed deterioration on seedling vigour in mango (Mangifera indica L.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2002) Anila, P; KAU; Girija, T
The present study on 'Impact of seed deterioration on seedling vigour in mango' was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during 1999-2001 with the objectives of assessing the variability of seedling characters obtained fr0111 a single plant, the effect of seed deterioration on seedling characters and to ascertain the critical moisture content of the varieties. Three varieties of mango were selected for the study. Assessment of variability of seedling characters of these varieties revealed that seedling girth is the most variable character, variability within varieties and between varieties was high for this character. Moreover, the response of girth to variation in seed weight due to loss in moisture content of the seed was also high indicating that this character may be influenced by both genetic factor as well as the physiological condition of the seed. The critical, moisture content was estimated to be 24% for Chandrakkaran, 30% for Moovandan and 28% for Puliyan. Seedling characters like height, girth, internodal length, number of leaves etc. were studied. These characters were found to be highly depended upon the moisture content of seed. There was considerable reduction in these characters with loss of moisture from seed. Polyembryonic nature of these varieties were not affected by seed desiccation. Biochemical characters like chlorophyll content, phenol content and sugar content were found to decrease with seed desiccation. Electrolyte leakage was found to be high with seed desiccation leading to reduction in viability. Seedling vigour was found to be positively correlated with biochemical characters.
Open Access
Legume pod borer resistance and genetic divergence in domestic germplasm of yard-long bean (Vigna unguiculata ssp. sesquipedalis(L.) Verdc.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Vidya, C; KAU; Sunny Oommen, K
The present study aimed at the evaluation of variability in domestic germplasm of yard-long bean for yield, and legume pod borer resistance was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Data for the investigation was collected from two field experiments conducted during the period 1998-2000. Fifty diverse genotypes of yard-long bean were evaluated for yield and related characters in a field experiment in randomised block design with three replications. Analysis of variance revealed significant differences among the varieties for all the twelve characters studied. High PCV and GCV were observed for yield of vegetable pods per plant, number of pods per plant, number of pods per inflorescence, length of main stem and pod weight. High heritability coupled with high genetic advance were also observed for these characters. Pod yield per plant showed high positive correlation with number of pods per plant, number of pods per inflorescence, pod weight and length of harvesting period. at genotypic level. Path analysis revealed that number of pods per plant and pod weight were the primary yield contributing characters owing to their high direct effect on pod yield. 2 So selection based on these characters will result in improvement of yield in yard-long bean. Based on Mahalanobis D2 statistic, the 50 cultivars were grouped into four clusters. Cluster I formed the largest cluster with 28 varieties while cluster IV had only a single cultivar. The genetic distance was maximum . ' between clusters I and IV and minimum between clusters III and IV. Cluster I had the highest intracluster distance. The single variety Vs 47 of cluster IV was identified as the highest yielder of green pods. Hybridisation of this variety with varieties having high pod number per plant or pod weight would be beneficial. The cultivars Vs 45 and Vs 49 belonging to cluster III possessed the highest pod weight and pod number per plant respectively. So hybridisation programmes utilising these varieties as parents is worthy of consideration for developing high yielding varieties in yard-long bean. In the field screening programme for legume pod borer resistance all the 50 yard-long bean cultivars were evaluated on the basis of overall plant resistance index (Ipr} computed using a combination of flower, pod and seed damage measurements viz., number of larvae in 25 flowers, percentage pod infestation and seed damage index (computed based on the number of damaged seeds in a sample of 25 pods) respectively. Cultivars showed significant differences among them for these damage . parameters as well as for resistance index computed based on them. The cultivars suffering least flower damage were Vs 5 and Vs 33. Lowest pod damage were recorded for the cultivars Vs 34, Vs 39 and Vs 42. Seed damage index value was the lowest for cultivar Vs 2. 3 Vs 34 with the lowest Ipr value was identified as the most resistant among the 50 yard-long bean varieties. The cultivars Vs 2, Vs 29, Vs 39 and Vs 42 were on par with Vs 34. Correlation analysis of the different damage parameters did not suggest any relationship between flower damage and pod damage or seed damage. However pod damage showed high positive correlation with seed damage. Cluster analysis based on the different damage parameters enabled to group varieties into seven clusters. Based on cluster means of the various damage parameters, cluster IV and I were those suffering least flower and pod damage respectively. So hybridisation programmes utilising varieties from these two clusters could lead to the production of varieties with higher level of legume pod borer resistance. Studies on relationship between pod damage and two pod characters viz., pod wall thickness and fibre content of pods indicated that these pod characters did not influence infestation and damage by legume pod borer. Based on superior yield performance and high level of resistance to legume pod borer, the cultivar Vs 42 is identified as a variety suitable for cultivation in legume pad borer endemic areas. Further, breeding programmes utilising the varieties with high yield and legume pod borer resistance identified in this study could help in evolving better yielding varieties with resistance to pod borer in yard-long bean.
Open Access
Genetics of bruchid (Callosobruchus sp.) resistance and yield in cowpea
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2001) Jyothi, C; KAU; Kanakamany, M T
The present study 'Genetics of bruchid (Callosobruchus sp.) resistance and yield in cowpea' was undertaken in the Department of Plant Breeding and Genetics, College of Horticulture, Kerala Agricultural University, Vellanikkara. The study was carried out to estimate the various genetic parameters of characters, to identify the yield components, to study association of characters related to pulse beetle resistance and to identify superior genotypes and hybrids having high yield and tolerance to pulse beetle. High variability among parents and hybrids was observed for most of the yield and bruchid resistance traits. The characters namely number of eggs laid, number of adult beetles emerged, number of bore holes produced, loss of weight per seed and tannin content exhibited higher values of heritability, genetic advance and genotypic coefficient of variation, indicating the preponderance of additive gene effects. A positive association was found to exist among yield attributes and also with yield in parents and hybrids. Genotypes having a thicker seed coat showed better resistance to pulse beetle attack and this character was found to be independent in gene action. Kanakamoni among the lines and EC 390231 among the testers were found to be the most promising genotypes for hybridization and selection since they recorded high positive gca. For heterosis breeding the crosses Kanakamoni x IC 201092 followed by C 152 x EC 390231 were found to be superior for pod yield. Kanakamoni and C 152 among the lines and EC 390231 and IC 201092 among the testers showed high tolerance to pulse beetle attack and are recommended for evolving resistant varieties using these genotypes through hybridization and selection. For evolving hybrids showing resistance to pulse beetle the crosses, C 152 x EC 367711 and V 240 x IC 201092 were rated supreme.

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