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Open Access
Characterization of long pepper (piper longum L) genotypes using morphological, anatomical and molecular markers
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2006) Jitha, Jaleel; KAU; Nandini, K
The present investigation entitled “Characterisation of long pepper (P. longum L.) genotypes using morphological, anatomical and molecular markers was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture ,Vellanikkara during the period 2003-2006. Six female and two male accessions formed the material for the study and were subjected to morphological, anatomical, and molecular characterization. The accessions showed variation in the morphology of vegetative and reproductive branches in leaf size, leaf shape and l/b ratio. Vegetative branches had large cordate leaves with petioles whereas reproductive branches had lanceolate leaves with rudimentary petiole. The l/b ratio of leaves of reproductive branches was higher compared to leaves of vegetative branch. The spikes of females were short, bold and greenish black on maturity whereas it was long, slender and yellow in the case of males. At early stages of spike growth, female spikes were creamy yellow and male green in colour. The stem, leaf, and root anatomy of the male and female accession showed almost similar features. The difference was noticed in the number of medullary and cortical bundles and the presence or absence of mucilage canals. Mucilage canal was present only in the female accessions, Assam, NL-84-68 and Viswam. The male and female spikes differ in their anatomical features. The physiological parameters revealed higher photosynthetic rate for the female accession, Viswam. The male accessions had lower photosynthetic rate compared to female accessions. RAPD analysis done on the eight accessions using five selected primers revealed 15 to 49% variability among the accessions at the molecular level and the primer OPF 5 produced male specific bands. The female accessions yielded maximum piperine and oil content at 60 -70 days maturity when they were greenish black and hard. Among the female accessions, Viswam, NL-84-68 and Assam recorded highest piperine and oil content. Low amounts of piperine and oil were found in male spikes also. Based on the study three female accessions, Viswam, NL-84-68 and Assam were found to be promising types and further breeding programmes can be carried out in these accessions to improve their performance.
Open Access
Exploration, collection and evaluation of brahmi (bacopa monniera wettst.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2006) Vishnuvardhan, Reddy Banda; KAU; Radhakrishnan, V V
The study on “Exploration, Collection and Evaluation of brami (Bacopa monniera wettst.) was undertaken during 2004-2006 at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, Kerala Agricultural University for evaluating the collected accessions from different eco-geographical locations of Kerala based on the morphological characters and the pharmaceutically important constituent i.e. bacoside-A. Twenty-nine accessions of Bacopa monniera collected from different eco-geographical locations were examined for genetic variability carried in them. The accessions were grown in pots, arranged in completely random block design, replicated twice, and observed for eight quantitative characters and bacoside-A content in the herbage. All the accessions were distinctly different irrespective of the geographical locations from where they were collected. The accessions were grouped into five clusters and the accessions showed no parallelism between clusters and geographical distribution. The bacoside-A content of the herbage was found to be low in the accessions possessing high internodal length and more number of flowers. Positive correlations for bacoside content was observed with shoot length, leaf length, leaf width, leaf area and biomass. The accessions, which flowered late, had good bacoside-A content. The accessions collected from Ernakulam district recorded good bacoside content when compared to accessions from other districts. The accession from Delhi recorded very trace amount of bacoside-A content. Bacoside content and biomass, which are very important for ayurvedic practioners had high heritabilities indicating the consistency of these two irrespective of the effect of the environment. It can be inferred that both the gross agroclimatic environment of the region and microenvironment in the vicinity of the water bodies where Bacopa monniera genotypes occur will regulate its growth and the content of bacoside-A.
Open Access
Study of reproductive biology and in vitro propagaton techniqes in kumizhu (gmelina arborea roxb)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2006) Sani, George; KAU; Dijee, Bastian
The present study ‘Study of reproductive biology and in vitro propagation techniques in kumizhu’ was undertaken in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during 2004-2006. The study comprised of two major experiments namely (i) Studies on reproductive biology and (ii) Studies on micro propagation The trees started blooming in January when new flushes sprouted out and continued upto the end of March. Inflorescence is a terminal cyme blooming in an irregular manner. The flowers are short stalked, pubescent, large, bisexual and scented. Calyx persistent, tubate and five lobed at tip. Corolla brownish yellow and has a short tube with the upper tip formed by two lateral petals. Stamens four, epipetalous. Anthers dithecous and dehisce longitudinally. Ovary bicarpellary, style long. Stigma short with two unequal lobes. Anthesis from late mid night to 3.00 am. Stigma receptive during anthesis and the receptivity lasts for 4-5 hours. Fruit set was absent under artificial selfing while under natural cross pollination upto 16.5 per cent fruit set was recorded. Fruit drupe with one strong seed. Seeds oval shaped, tapering to one end. MS medium was best medium suited for callus induction and bud expansion. Nodal segments were the explants for direct organogenesis and for indirect organogenesis. Surface sterilization was done by soaking explants in 70 per cent alcohol for 30 seconds, followed by soaking in HgCl2 0.1 for 4 minutes. MS+BA 5 mg/l+NAA 0.5 mg/l produced leaf bud expansion. Pronounced callus formation was observed when explants were inoculated on medium containing 2, 4-D at various levels (0.5 mg/l to 2 mg/l). BA upto 3 mg/l and kinetin upto 1 mg/l induced callusing. WPM was found to be more suited for callus proliferation as the time for response was almost half of that of MS medium. WPM supplemented with adenine recorded maximum callus proliferation.
Open Access
Genome analysis of traditional rice varieties of Kerala using ISSR and RAPD markers
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Reshmi, Manohar; KAU; Jayalekshmy, V G
The research project “Genome analysis of traditional rice varieties of Kerala using ISSR and RAPD markers” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, Thiruvananthapuram during 2004-2006. The major objectives of the study were to characterize indigenous rice collection of Kerala on the basis of two molecular markers viz. ISSR and RAPD and to assess the genetic diversity using molecular marker technique. The study using RAPD markers produced 222 amplicons of which 182 were polymorphic thus giving a polymorphism of 81.98 per cent. Twenty primers were used for the study. Of these the primer OPF-04 gave maximum number of polymorphic products and also produced two unique positive products in the accession Cheruvirippu (size between 1.0 kb and 1.5 kb) and in the accession Njavara yellow (size of less than 0.5 kb). The amplification products had size ranging from 2.0 kb to less than 0.5 kb. The analysis produced nine unique positive products and seven unique negative products. Clustering based on Jaccard’s similarity coefficient revealed the highest similarity between the accessions Chettivirippu and Pokkali 3 (0.825). The least similarity index of 0.451 was between the accessions Cheeravithu and Vellakkoli. The Njavara group of accessions, Njavara yellow and Njavara black, clustered at a similarity value of 0.707. The primer OPB-05 and OPF-01 could distinguish the Njavara accessions from others. OPB-05 produced unique product with a size of less than 1.0 kb and OPF-01 produced product at size of less than 0.5 kb. ISSR analysis was carried out using two primers. The amplification using the two primers produced 19 amplicons of which 16 were polymorphic giving 84.21 per cent polymorphism. The amplification products had size ranging from 0.2 kb to more than 1.0 kb. A unique negative marker was amplified by the primer (GA) 8T in the accession Karuthacheera with a size of nearly 0.6 kb. The UPGMA clustering was done using Jaccard’s similarity coefficient values. The highest similarity of 1.00 was shown by the accessions, Athikiramundakan and Veluthakattamodan and by Vellamundakan and Chettivirippu. The least similarity was between the accessions Karuthacheera and Pandivella (0.230). The accession Karuthacheera was unique and formed a single cluster at similarity value of 0.420. The pattern of clustering for the individual marker systems did not show any congruence with each other. However the cluster analysis of combination of the two marker systems produced a better picture of the genetic relationship. The present study using the two dominant DNA markers, RAPD and ISSR, showed that both the DNA markers are effective and promising for detecting genetic variation. It has been observed that ISSR is superior to RAPD in terms of polymorphism detected.
Open Access
Invitro studies on selected genotypes in Anthurium andreanum linden
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Julie, Alex; KAU; Mayadevi, P
Studies were conducted to standardize in vitro propagation techniques via, somatic organogenesis in Anthurium andreanum varieties (Liver Red, Acropolis White, Tropical Red and OO  KR) during 2004-2005 in the Department of Plant Breeding and Genetics and Department of Plant Biotechnology, College of Agriculture, Vellayani. All the four varieties responded to callusing treatments in varying degrees. Regeneration was obtained only in the varieties Liver Red and Acropolis White and these two varieties were subjected to different treatments for the refinement of callusing and shoot proliferation. The protocol for in vitro propagation of these two varieties could be standardized. Surface sterilization of leaf explants with mercuric chloride 0.1 per cent for eight minutes gave 91.08 per cent sterile cultures. Mercuric chloride 0.1 per cent for 10 minutes was best for surface sterilization of petiole explants. Spadix explants required longer period of surface sterilization (Mercuric chloride 0.1 per cent for 15 minutes). Among the three different explants tried only leaf explants were found responsive to callusing. Whereas petiole and spadix explants showed only swelling even after two months of culturing. 57.45 per cent cultures initiated callus within 62.4 days in Acropolis White and 70.97 per cent of cultures initiated callus within 63.1 days in Liver Red, when the leaf explants were cultured in darkness on modified MS medium supplemented with NH4NO3 200 mg l-1 + 2,4-D 0.5 mg l-1 + BA 1.0 mg l-1 + sucrose 30.0 g l-1 + agar 6.0 g l-1 . The callus cultures were subcultured in the same medium for two months for callus multiplication. Shoot regeneration was occurred when cultures were subcultured to MS basal medium supplemented with BA 1.0 mg l-1 + IAA 3.0 mg l-1 + sucrose 30 g l-1 + agar 6.0 g l-1. In Acropolis White (71.07 per cent) and in Liver Red (84.41 per cent) of cultures initiated shoots within 72.7 days and 76.7 days respectively. Light was essential for regeneration. Shoot proliferation occurred within one month when the cultures subcultured to the same medium (MS + BA 1.0 mg l-1 + IAA 3.0 mg l-1 + sucrose 30 g l-1 + agar 6.0 g l-1) supplemented with casein hydrolysate 150 mg/l. Improvement in the growth of shoots and leaf were obtained by incorporating activated charcol (1.0g/l) to the medium. A separate rooting medium was not necessary since satisfactory rooting was obtained in the shoot proliferation medium itself.
Open Access
Genetic analysis of yield and fusarium wilt resistance in line x tester progeny of yard long bean (vigna unguiculata subsp. sesquipedalis (L) verdcourt)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Renjana G, Nair; KAU; Radhadevi, D S
A research programme was carried at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 2004-2006 with the object of studying the combining ability variances and the nature of gene action involved in important quantitative and biochemical characters and Fusarium wilt resistance in line x tester progenies of yard long bean. Based on the previous PG project entitled “Genetic variability for yield and Fusarium wilt resistance in yard long bean (Vigna unguiculata subsp. sesquipealis (L.)Verdcourt)”, five lines having high yield and moderate fusarium wilt resistance and three testers having high fusarium wilt resistance was selected as parents. They were crossed in Lx T pattern and seeds of F1s and parents were laid out in Randomised Block Design with three replications. The fifteen crosses along with their parents were evaluated for mean performance, combining ability, gene action and heterosis based on 22 characters namely, days to 50% flowering, days to first harvest, length of harvest period, crop duration, primary branches per plant, main stem length, pod clusters per plant, pods per plant, pods yield per plant, pods per cluster, pod weight, pod length, pod breadth, seeds per pod, 100 seed weight, fresh weight of roots per plant, nodules per plant, crude fibre content, protein content, peroxidase, polyphenol oxidase and total phenols. Significant differences among treatments were observed for all characters especially pod yield per plant. The magnitude of sca variance alone was significant suggesting the importance of the dominance gene action in controlling the quantitative and biochemical characters of yard long bean. Based on the mean performance and gca effects,VS-86 was found to be good general combiner among lines and TVM-1 among testers. The cross, P-1x TVM-1 was found to be promising for main stem length,100 seed weight and polyphenol oxidase and VS-86 x TVM-1 was superior for pod yield per plant based on mean performance, sca effects and standard heterosis. Hence these crosses can be advanced for further trials for developing superior yard long bean varieties. The pot culture experiments done for screening Fusarium wilt resistant genotypes by artificial inoculation of pathogen revealed that treatments were highly significant. Least mortality was shown by the line P-1, tester TVM-1 and cross VS-86 x TVM-1 followed by Varuvila-2 x TVM-1 and P-1 x TVM-3. Critical assessment of results suggests ample scope of improvement of yield and fusarium wilt resistance through selection based on combining ability and heterosis. Three superior crosses, VS-86 x TVM-1, P-1 x TVM-1 and Vellayani x TVM-1 were identified which were high yielding and reduced disease incidence. Among these VS-86 x TVM-1 was found to be most superior. Thus the work can be continued with these crosses for evolving varieties superior for yield and fusarium wilt disease resistance.
Open Access
In vitro multiplication and molecular characterization of selected dendrobium hybrids
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Rahana, S N; KAU; Lekha Rani, C
Attempts were made to undertake initial culture establishment and molecular characterization of 40 selected Dendrobium hybrids developed in the Department of Plant Breeding and Genetics under a DBT funded orchid breeding project and to refine the protocol for rapid multiplication using in vitro leaf explants. The studies were carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2004-2006. Initial culture establishment of the 40 selected Dendrobium hybrids were carried out using stem nodal explants obtained from keikis and were inoculated in the identified best media, viz., VW + KN 4 mg l-1 + IAA 4 mg l-1 + CW 200 ml l-1 (Sivamani, 2004). The nature of response of the stem nodal explant was found to be varied among the hybrids. The duration taken for the initiation of PLBs, shoot, leaf and root differed significantly among the hybrids. Once the PLBs or shoot buds had been differentiated, the cultures were transferred to the subculturing media for faster growth and development. Leaves and roots appeared from the shoot buds or PLBs after four to ten weeks in culture. The plantlets obtained were hardened and transferred to the greenhouse. Plantlets obtained through stem nodal cultures were more vigorous than that from in vitro leaf explant cultures. The regeneration potential of in vitro sourced leaf explants appeared to be an inherent trait of orchids which gets evoked under certain physico-chemical stimulus under in vitro condition. The in vitro sourced leaf explants can be profitably used for micropropagation. The main advantage of this technique is that in selected single plant hybrids where keiki production is low, once they are established in vitro, they can be further mass multiplied using the in vitro leaf as explant. The young leaf segments derived from in vitro established Dendrobium hybrids were used as explant. Swelling of cut leaf edges and callus initiation studies were conducted with two levels of CH (500 mg l-1 and 250 mg l-1) in half strength MS medium containing BAP 5 mg l-1 + KN 5 mg l-1 + CH 500 mg l-1 + CW 200 ml l-1 + AC l gl-1. Out of this CH at 500 mg l-1 was found to be the best for callus initiation and subsequent development of plantlet. The callus obtained from the inoculation medium, irrespective of the levels of CH used, were grouped together and cultured on regeneration media with two different levels of CH, viz., CH at 250 mg l-1 and no CH. Presence of CH at 250 mg l-1 was found to have significant effect on shooting response. The optimum medium combination for shoot initiation was found to be half strength MS medium with BAP 5 mg l-1 + KN 5 mg l-1 + CH 250 mg l-1 + CW 200 ml l-1 + AC 1 gl-1. Out of the different strengths of MS medium tried with in vitro leaf explant, half strength MS medium exhibited early establishment of plantlet and recorded minimum number of days for deflasking. Half strength MS with NAA 0.1 mg l-1 + BAP 0.5 mg l-1 + AC 1 gl-1 + CW 200 mg l-1 was found to be the best medium combination for better in vitro rooting and early establishment of plantlet. Plantlets were ready for plant out in six months. Random amplified polymorphic DNA (RAPD) analysis was employed for the molecular characterization of the 40 selected Dendrobium hybrids. The eight primers, selected from the 40 initially screened primers, generated 69 scorable bands of which three were monomorphic and the remaining 66 were polymorphic (95.65 %). All primers produced polymorphic amplification products, however, the extent of polymorphism varied with each primer. Statistical analysis was carried out using NTSYS-PC software and a dendrogram was generated using Jaccard’s similarity coefficients. The overall similarity coefficient ranged from 0.29 to 1.00. The forty selected Dendrobium hybrids that were studied formed 11 clusters in UPGMA cluster analysis. The grouping of hybrids in the cluster was largely consistent with what is known about their breeding history. The cluster based on RAPD analysis using eight primers clearly demonstrates the existence of genetic variation within the 40 selected Dendrobium hybrids. Polymorphism obtained in the present study can be used as fingerprints of the forty selected Dendrobium hybrids.
Open Access
Genetic divergence in cluster bean (Cyamopsis tetragonoloba (L.) Taub.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Anandhi, K; KAU; Sunny K, Oomen
The present study aimed at evaluating a collection of clusterbean (Cyamopsis tetragonoloba (L.) Taub.) genotypes for yield and related characters and grouping of genotypes was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 2003-2004. Twenty nine genotypes of clusterbean were evaluated for yield and yield related characters in randomized block design with three replications. The analysis of variance revealed significant differences among the varieties for all the characters studied which include days to 50 per cent flowering, plant height, number of primary branches, number of pod clusters per plant, number of pods per cluster, pod weight, pod length, number of seeds per pod, number of pods per plant and yield per plant. High values of PCV with correspondingly high values of GCV were observed in the present study for number of pod clusters per plant, number of pods per plant, number of pods per cluster and yield, which indicated the existence of high degree of genetic variation and ample scope for improvement of these characters through selection. High values of heritability coupled with high genetic advance was observed for number of pod clusters per plant, pods per plant, pod yield and number of pods per cluster suggesting additive gene action for these traits. There is immense scope for improvement of number of pod clusters per plant and number of pods per plant through selection on account of their high magnitude of heritability and exceptionally high genetic advance. Vegetable pod yield showed high positive genotypic correlation with the characters number of pods per plant, number of seeds per pod, pod weight and number of pod clusters per plant. Path coefficient analysis revealed number of pods per plant and pod weight are the characters with high direct effect. These two characters had got high indirect effect on yield through number of pod clusters per plant and number of seeds per plant respectively. Hence these characters can be identified as the major characters contributing towards pod yield and selection based on these characters would be effective for developing high yielding varieties of clusterbean genotypes. Based on Mahalanobis statistic, the 29 genotypes of clusterbean were grouped into four clusters. Cluster II was the largest with 10 genotypes. Intercluster distance was observed maximum between clusters I and IV while the close proximity was noticed between the clusters II and III. Cluster IV having the single variety Ct 11 exhibited the maximum mean value for yield per plant, number of pods per plant and number of clusters per plant indicating that this cluster is superior to the others with respect to these characters. Cluster II having Ct 7 was superior for pods per cluster, pod weight and days to 50 per cent flowering. On the basis of selection index the genotypes IC 10350 (Ct 11) and IC 8423 (Ct 7) recorded highest index value. Hybridization of the superior genotype Ct 11 of cluster IV with Ct 7 of cluster II having high pod weight would be beneficial for evolving high yielding genotypes.
Open Access
Screening for leaf curl virus disease complex resistance, genetic evaluation and molecular characterization of bird chilli (Capsicum frutescens L.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Nicey, Mathew; KAU; Abdul Khader, K M
The investigation entitled “Screening for leaf curl virus disease complex resistance, genetic evaluation and molecular characterisation of bird chilli (C. frutescens L.)” was conducted at Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, Thiruvananthapuram during 2003-2005. The data for the investigation were collected from two field experiments, each laid out in Randomized Block Design with three replications. The second experiment was conducted without taking any control measures against leaf curl virus disease. The 49 genotypes included in the study showed significant difference for all the 14 biometric characters. They all showed high heritability coupled with high genetic advance except days to first flowering for which the genetic advance was moderate. The maximum values for phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were recorded for fruit yield per plant and individual fruit weight respectively and the minimum values for days to first flowering. Fruit yield per plant was positively correlated with number of fruit per plant, number of secondary branches, plant spread, 100-seed weight, number of primary branches, number of seeds per fruit, individual fruit weight, fruit length, fruit width and plant height. Path analysis revealed high positive direct effect of individual fruit weight and number of fruits per plant on yield per plant. Hence selection for these characters can improve the yield. The 49 genotypes were grouped into five clusters based on Mahalanobis D2 statistic. Cluster I was the largest with 29 genotypes while clusters IV and V had only one genotype each. Clusters II and III had 11 and eight genotypes respectively. Cluster I was found to be superior to the other clusters with respect to the desirable characters. The genotypes were ranked based on the selection indices. High yielding and superior genotypes had high selection indices while low yielding genotypes were having low selection indices. Field screening of 49 genotypes for leaf curl virus resistance (experiment II) showed that five genotypes were highly tolerant to the disease while 14 genotypes were susceptible and 30 were highly susceptible. Comparison of yield and vulnerability index in both the experiments showed that reduction in yield was less in tolerant varieties than in susceptible varieties. The yield performance of Karumukku local, Thavanur local 3 and Meenachil local were comparable under controlled and uncontrolled conditions. Correlation analysis showed negative association of yield with vulnerability index in both experiments indicating that susceptibility to the disease leads to reduction in yield. The high yielding and leaf curl tolerant types identified from the study can be used as parents in crop improvement programme to evolve high yielding, leaf curl tolerant varieties. RAPD analysis was performed using the random primers OPA-01, OPB-01, OPB-06 and OPB-10 and the 49 genotypes were characterized using Jaccard’s similarity coefficient analysis and a dendrogram was constructed to cluster the genotypes. The high yielding genotypes T1 (Karumukku local) and T15 (Thavanur local 3) came in the same cluster (cluster II) while the leaf curl virus tolerant genotypes T35 (Kayamkulam local 3) and T33 (Kayamkulam local 4) came in the other cluster (Cluster I).

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