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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Genetics of shattering resistance in rice (Oryza sativa L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2020) Akhil, K P; KAU; Biju, SRice is the staple food crop of Kerala. Among the plethora of rice varieties available Jyothi is by far the most popular in the state owing to its consumer preference. Easy seed shattering leads to significant loss in Jyothi which can be overcome by transferring shattering resistance to it. Screening of genotypes for shattering resistance identified donors like Athira and Triveni with good combining ability. The present experiment was thus envisaged to transfer shattering resistance to Jyothi from the donors and to study the nature of inheritance of seed shattering trait using six parameter model of generation mean analysis. Observations were recorded in the two crosses viz., Jyothi x Aathira and Jyothi x Triveni for eleven quantitative characters viz. days to 50 per cent flowering, plant height, tillers per plant, panicles per plant, panicle length, spikelets per panicle, seeds per panicle, days to maturity, test weight, grain yield per plant and shattering per cent in six generation (P1, P2, F1, F2, B1 and B2) obtained from the two crosses. Panicle per plant, test weight, grain yield per plant and shattering per cent recorded significant heterosis in the desirable direction in both the crosses. Mean effect (m) was significant and positive for all the characters studied in both the crosses. The additive component (d) was significant and positive for days to 50 per cent flowering, tillers per plant, panicles per plant, days to maturity, grain yield per plant and shattering per cent in the cross Jyothi x Triveni while the other characters recorded significant and negative additive gene effect. The characters tillers per plant, test weight and shattering per cent showed significant positive additive gene effect in the cross Jyothi x Aathira and rest of the characters showed significant and negative additive component. Dominance gene effect was observed to be significant and negative for most of the characters studied in both the crosses. Non-allelic interactions were observed to be significant in most of the characters except days to 50 per cent flowering, tillers per plant, days to maturity and shattering per cent in the cross Jyothi x Aathira. The epistatic interaction model of generation mean analysis was found adequate for obtaining gene actions for all the characters. Among the three type of interactions dominance x dominance interaction was found to be more important for all the characters. Additive x additive and additive x dominance gene interactions were found to be equally important for most of the characters studied in both the crosses. Dominance gene effect was observed controlling the genetic variance in most of the traits studied. Presence of additive and non-additive along with epistatic interaction revealed the complex nature of inheritance of the characters. Predominant dominant gene effect along with duplicate epistasis limits the scope of direct selection. In the F2 populations characters showed high heritability in both the populations studied. Plant height, panicle length and days to maturity were found to have low genetic advance. Plant height recorded moderate genetic advance, whereas, other characters exhibited high genetic advance in F2 population derived from the cross Jyothi x Triveni. Days to maturity showed low genetic advance, days to 50 per cent flowering and panicle length recorded moderate genetic advance and other characters recorded high genetic advance in F2 population derived from the cross Jyothi x Aathira. As shattering resistance is governed predominantly by additive gene effects selection in the early segregating generations will be highly rewarding. The selected lines may be advanced to further generations to identify lines with high yield coupled with shattering resistance and can be forwarded to develop high yielding varieties with low shattering or bi-parental mating among the selected lines may be undertaken to recover superior recombinants with high yield and shattering resistance.ThesisItem Open Access Development of doubled haploids for iron toxicity tolerance in rice (Oryza sativa L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2020) Chakravarthi, Marri; KAU; Dijee, BastianRice is the staple food crop of the people of Kerala. The production of rice in Kerala is impeded by many biotic and abiotic stresses. Iron toxicity is one of the major abiotic stresses of acidic soils in Kerala. The present study “Development of doubled haploids for iron toxicity tolerance in rice (Oryza sativa L.)” was taken up with the objective of developing doubled haploids with tolerance to iron toxicity through in vitro anther culture. Doubled haploids being homozygous stable lines, can be used both as immortal populations for QTL mapping as well as varieties, if suitable agronomic traits are present in them. Therefore, this study was taken up which comprised of three experiments. In experiment I, two tolerant genotypes (Swetha and Mangala Mahsuri) and two susceptible genotypes (Cul-90-03 and Cul 8709) were crossed with Tulasi. In the second experiment the parents along with their hybrids were evaluated for biometric characters and yield. The hybrids obtained from the crosses were significantly different for all the characters observed. Panicles per plant and grain yield per plant recorded highly significant and positive relative heterosis and heterobeltiosis. The anthers from the F1s produced in the previous experiment were used for anther culture studies in the third experiment. Sterilisation with various sterilants like 70 % ethanol, 0.1 % mercuric chloride, 5.25% sodium hypochlorite and their combinations were done. Explant sterilisation with 5.25% sodium hypochlorite for 5 to 20 minutes was effective in controlling contamination in the in vitro cultures. Study to know the best number of days of cold pre-treatment at 10oC was done (0, 3, 6, 9, 12, 15 days). Cold pre-treatment of anthers at 10oC for 9 days was found to be optimum for most of the genotypes studied. Two different media viz., N6 and B5 were tried with different combinations of 2,4 - D and Kn. N6 media responded better than B5 media for callus induction in all the growth hormone combinations. The effect of carbon source on callusing was studied using maltose and sucrose at various levels (30,40,50 mg/L) and it was found that maltose at 30g/L gave the best callus induction (7.95%). Among the auxins used in the present study,2,4-D was found to be better than NAA for callus induction while among cytokinins, Kinetin responded better than BAP for callus induction. The growth hormone combination 2,4- D (2mg/L) + Kn (0.5mg/L) was adjudged the best for callus induction. Additives like silver nitrate (AgNO3), casein hydrolysate (CH), yeast extract (YE), proline and activated charcoal were added to the basal media to improve callusing. when AgNO3 is applied from 0 to 1ml with 0.1 ml gradation, 0.5-0.6ml of 0.1N AgNO3 was found to be better in callus induction as well as the days to callus induction was reduced at these concentrations. 250 – 500 mg/L of CH and 250mg/L proline were found to induce significant response for callusing while activated charcoal and yeast extract did not have any considerable effect on callus induction. Hybrid H1 recorded good callus response when maltose at three levels was tried in the media (30, 40, 50g/L) whereas hybrid H2 gave uniform response at all the levels of maltose. There was significant variation among the genotypes in their response to all the factors studied. The best responses were as follows: - H1(Swetha x Tulasi) - N6+2,4-D (2mg/L) + Kn (0.5mg/L) + 30g/L maltose +0.5ml (0.1 N AgNO3) + 250mg/L proline + 250mg/L CH +2.5g/L gelrite gellan gum. H2(Mangala Mahsuri x Tulasi) - N6+2,4-D (2mg/L) +Kn (0.5mg/L) + 30g/L maltose +0.5ml (0.1N AgNO3) +250mg/L proline+250mg/L CH +2.5g/L gelrite gellan gum. H3(Cul-90-03 x Tulasi) - N6+2,4-D (2mg/L) +Kn (0.5mg/L) + 30g/L maltose + 0.5ml (AgNO3) + 250mg/L proline + 250mg/L CH + 2.5g/L gelrite gellan gum. H4(Cul 8709 x Tulasi)- B5 + 2,4-D (2mg/L) + Kn (0.5mg/L) + 30g/L maltose + 0.5ml (0.1N AgNO3) + 250mg/L proline + 250mg/L CH + 2.5g/L gelrite gellan gum. The calli obtained from the different genotypes were plated on two different callus regeneration media R1 (MS+ NAA(1mg/L) + Kn (2mg/L) + IAA (0.5mg/L) + CW (5%)) and R2 (MS+NAA (0.25mg/L) + BAP (0.75mg/L) + Kn(0.25mg/L)). There was no response in R1 media. Callus regenerated into plantlets in R2 but all the plantlets obtained were albinos leading to mortality and hence plantlet hardening and field planting could not be undertaken.ThesisItem 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 BastianAn 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.ThesisItem Open Access Marker assisted backcross breeding for pyramiding genes conferring resistance to bacterial blight in rice variety uma(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2018) Megha, L M; KAU; Rose Mary FranciesAs in other rice growing locales around the world, bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) assumes a huge role in deciding rice profitability in Kerala. The elite rice varieties of Kerala, both PTB 39 (Jyothi) and Mo 16 (Uma), are found to be extremely susceptible to bacterial blight. Since both the major rice cropping seasons (virippu and mundakan) in the state coincide with monsoons, the control of the disease through chemicals or biological agents proves inadequate owing to the washing-off of the applied materials. Host-plant resistance is advocated as the most effective breeding strategy to combat the bacterial blight (BB) pathogen. Considering the impact of the disease on food security and sustainability, efforts were taken to introgress three R-genes (xa5, xa13 and Xa21) into the variety Uma from donor parent Improved Samba Mahsuri (ISM) through Marker Assisted Selection (MAS). Further, backcrossing to Uma (recurrent parent) and advancing the resultant BC1F1s have resulted in production of BC2F1 generation (21 Nos.). The present study aimed to identify BC2F1 plants pyramided with genes (xa5, xa13 and Xa21) conferring resistance to bacterial blight using functional markers. In addition, advancing the R-gene introgressed BC2F1s to BC3F1 and BC2F2 generation was envisaged. Pathotyping of BC1F2s (850 Nos.) and generating BC1F3s from the plants exhibiting resistance to BB pathogen was also aimed at. Foreground selection of the BC2F1 individuals using the xa5 gene linked STS marker RG 556 and functional marker xa5 SR confirmed the presence of the R-gene in the parents as well as the 21 BC2F1 individuals. Screening of BC2F1 individuals with STS marker RG 136 linked to R-gene xa13 and functional marker xa13 promoter revealed that the BC2F1 Plant No. 8.3.9.10 was heterozygous at xa13 locus while, all other BC2F1 individuals possessed alleles similar to that of the recurrent parent (RP) Uma. The result also pointed out that BC2F1 Plant No. 8.3.9.10 was a 2-R-gene pyramid (xa5xa5 + Xa13xa13). Foreground selection with STS marker pTA 248 to detect the presence of Xa21 gene revealed that none of the BC2F1 plants analysed except BC2F1 Plant No. 8.3.9.10, possessed the resistant allele of R-gene Xa21. However, presence of alleles of both the parents in Plant No. 8.3.9.10 indicated that it was heterozygous at Xa21 locus. Results obtained thus revealed that, of the 21 BC2F1s subjected to foreground selection, BC2F1 Plant No. 8.3.9.10 was the only 3-R-gene introgressed pyramid (xa5xa5 + Xa13xa13 + Xa21xa21). In addition, the 3-R-gene introgressed BC2F1 Plant No. 8.3.9.10 was subjected to background screening using 22 rice microsatellite (RM) markers. Background profiling revealed that the banding pattern in Plant No. 8.3.9.10 was similar to recurrent parent in case of thirteen RM markers. The plant was found to be heterozygous at five other marker loci. Considering the segregation of the 22 markers, the magnitude of recovery of recurrent parent genome in 3-R-gene introgressed BC2F1 Plant No. 8.3.9.10 was found to be 81.82 per cent. The dendrogram based on molecular data grouped the individuals into two major clusters. Cluster 1 was monogenic with only the donor parent ISM and cluster 2 comprised of the recurrent parent Uma and Plant No.8.3.9.10, further suggesting that the 3-R-gene introgressed BC2F1 Plant No. 8.3.9.10 was more similar to the recurrent parent Uma. Wide variability was observed among the BC2F1 individuals for various morphological traits. The 3-R-gene introgressed BC2F1 Plant No. 8.3.9.10 was shorter in duration than both the parents and also possessed red kernels similar to the recurrent parent Uma. The dendrogram generated based on the morphological characters also indicated greater similarity between the 3-R-gene pyramid and recurrent parent Uma. The identified 3-R-gene pyramid (BC2F1 Plant No. 8.3.9.10) was backcrossed to both recurrent parent Uma as well as selfed resulting in production of BC3F1s (15 Nos.) and BC2F2s (28 Nos.) respectively. Bioassay of BC1F2 population (106 Nos.) through leaf clipping method of pathotyping suggested by IRRI (1991) revealed that more than half the BC1F2 individuals screened exhibited resistance to BB pathogen. The plants that exhibited moderate reaction to BB infection ranged between 16.87 per cent and 34.78 per cent in progeny of BC1F2 Plant No. 8.3.2 and BC1F2 Plant No. 8.3.9 respectively. Selfing of the BC1F2 individuals exhibiting resistance and moderate resistance to BB pathogen resulted in production of 725 BC1F3 seeds. Modern molecular techniques make it possible to use markers and probes to track the simultaneous introgression of several R-genes into a single cultivar during a crossing programme. Foreground and background profiling of backcross generations can ensure precise identification of R-gene introgressed genotypes that resemble the recurrent parent Uma.ThesisItem 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 RCharacterisation 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.ThesisItem 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, KThe 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.ThesisItem 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 OmmenOkra 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.ThesisItem Open Access Compatibility studies in monopodial orchids(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Ninitha Nath, C; KAU; Lekha Rani CA 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.ThesisItem 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, PGenetic 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.
