Browsing by Author "Seeja, G"

Now showing 1 - 7 of 7

Combining ability studies in tomato (lycopersicon esculentum mill)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Seeja, G; Chandramony, D
An experiment in tomato (Lycopersicon esculentum Mill.) was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1993-94, with the objective of estimating the combining ability of parents and gene action, involved in the inheritance of different yield attributes. The study was conducted in a line x tester model, using three bacterial wilt resistant varieties as lines and five popular varieties as testers. The three bacterial wilt resistant varieties (lines) were Arka Abha, Arka Alok and Sakthi. The five popular varieties (testers) were LE 312, LE 370, LE 373, RFH-1 and PKM-1. These eight parental varieties and 15 hybrids were planted in the field in RBD, with three replications. Observations recorded were plant height, number of branches/plant, growth habit, spread of the plant, period of harvest, individual fruit weight, number of fruits/plant, fruit yield/plant, number of leaves/plant, pericarp thickness, locules/fruit, size of fruit and pest and disease incidence. Analysis of variance revealed highly significant differences among the genotypes for all the characters. Gca alone was significant for number of branches/ plant while sca alone was significant for spread of the plant and pericarp thickness. Both gca and sca were significant for the remaining characters such as plant height, period of harvest, individual fruit weight, fruits/ plant, fruit yield/plant, leaves/plant, locules/fruit and size of fruit. The additive to dominance variance ratio indicated a preponderance for non additive gene action in the above characters. Combining ability analysis showed that all the three lines viz., Arka Abha, Arka Alok and Sakthi were good general combiners with respect to fruit yield and other yield attributes whereas the testers were good general combiners, for the different vegetative characters such as plant height, branches and leaves/plant. Among the 15 hybrids combinations, significant sca and heterosis were observed in the hybrids such as Arka Abha x LE 370, Arka Alok x PKM-1, Arka Alok x LE 312, Arka Abha x RFH-1 and Sakthi x RHF-1. Among these hybrids, Arka Abha x LE 370 showed significance for fruit yield, individual fruit weight, size of fruit, plant height, leaves/plant, branches/plant and also showed resistance to mosaic, leaf cur1 and fruit borer. This hybrid exhibited indeterminate growth habit. The hybrid Arka Alok x PKM-1 showed significance for fruits/plant, fruit yield/plant, plant height and leaves/plant. The combinations Arka Alok x LE 312 and Arka Alok x RFH-1 showed high sca and heterosis for individual fruit weight, fruit size and pericarp thickness, and also high heterosis for fruit yield/plant. Among these, Arka Aloka 312 showed indeterminated growth and Arka Alok x RFH-1 showed semi determinate growth habit. Sakthi x RFH-1 exhibited high sca for fruit yield/plant and heterosis for fruit number and individual fruit weight. This hybrid also showed resistance to leaf curl and mosaic. This hybrid showed determinate growth habit. Therefore these hybrids can be utilized for further crop improvement programme.
Combining yield and leaf curl-mosaic complex virus tolerance in Chilli
(Department of Genetics and Plant breeding, College of Agriculture, Vellayani, 2026-02-16) Varsha, P Vengilat; Seeja, G
Chilli (Capsicum spp.) is a widely cultivated crop in India, valued for its economic and culinary significance as vegetables, spices, and in industrial applications such as the production of oleoresins. It is grown for its fresh green and dried red fruits. India is one of the largest producers, consumers, and exporters of chilli, with major growing states including Andhra Pradesh, Telangana, Karnataka, Tamil Nadu, and Maharashtra. Despite its significance, chilli production in India faces several challenges, primarily due to the prevalence of diseases that adversely affect yield and quality. Chilli Leaf Curl Mosaic Complex (CLCMC) is one of the most severe viral diseases affecting chilli (Capsicum spp.) production, especially in tropical and subtropical regions like India. This disease results from a synergistic interaction between multiple viruses, primarily the Chilli leaf curl virus (ChiLCV), a member of the Begomovirus genus, often in association with Tomato leaf curl virus (ToLCV), and sometimes with other satellite molecules or helper components. In severe cases of disease infection, up to 100 percent loss in marketable yield has been reported. Hence, a study entitled ‘combining yield and leaf curl mosaic complex virus tolerance in chilli’ was carried out in the Department of Genetics and Plant Breeding, College of Agriculture, Vellayani during 2020-2024, with the objective of identification of superior cross combinations for leaf curl-mosaic complex virus tolerance, yield and yield attributes in chilli. In the first experiment, a total of sixty-four genotypes, collected from National Bureau of Plant Genetic Resources, Kerala Agricultural University and farmers’ field were screened for natural incidence of chilli-leaf curl-mosaic complex disease in cubic lattice design during the summer of 2023. The highest mean yield per plant (g) was shown by Paal Mulaku (Kumarichanda Local). The genotypes showed significant differences for all the traits under study indicating the presence of substantial genetic variability. These sixty-four genotypes were classified into nine clusters based on Euclidean2 method. A modified disease scoring scale of zero to five was developed for leaf-curl mosaic complex disease by combining the disease scores of chilli leaf curl and cucumber mosaic virus. Disease incidence and severity calculated as vulnerability index were calculated based on disease scoring. The genotypes were classified into immune, tolerant, highly resistant, resistant, susceptible and highly susceptible based on the vulnerability index. Ten genotypes showed immune reaction, while twenty showed tolerance to CLCMC. Hence, a total of thirty genotypes were selected for artificial screening against CLCMC in pot culture experiment. Graft transmission technique was adopted for artificial inoculation during experiment II. The viruses were transmitted from the diseased Vellayani Athulya, used as scion, to the genotypes selected from experiment I, used as rootstocks. Six out of the eleven genotypes that were found to be immune to the disease complex belonged to the top ten high yielding genotypes. Hence, genotypes namely, Venjaramood Local II, KD 2, Unda Chilli (Vadakara Local), AP-1, IC-208580 and IC-570376 were selected as parents for the hybridization program to combine high yielding character and tolerance to chilli leaf curl-mosaic complex disease. Of these the genotype IC-208580 belongs to C.frutescens and Venjaramood Local II, KD-2, Unda Chilli (Vadakara Local), AP-1and IC-570376 belong to C.annuum. The virus titre was estimated based on virus specific primers. No amplification was obtained for the six genotypes when chilli leaf curl virus coat protein specific primer, CLA 7F/CLA 8R was used for the titer estimation while three genotypes showed amplification when degenerate Deng primer was used. This may be attributed to the ability of genotypes to suppress the disease symptom expression. The molecular markers reported to be linked to the diseases were validated in the second part of experiment II. SSR Markers namely PAU-LC-343-1, CA 516044, AVRDC MD*850 and AVRDC-PP188 were reported to be linked to the chilli leaf curl disease resistant gene. SSR Marker HpmsE003 was reported to be linked to cucumber mosaic virus resistance gene. All the markers showed polymorphism between resistant and susceptible genotypes. SSR marker HpmsE003 linked to cmr1 locus, also showed polymorphism between resistant genotypes and susceptible check. The six genotypes were hybridized in a diallel fashion during experiment III. A total of thirty cross combinations were made, with six parents, of which ten cross combinations were interspecific crosses (Capsicum frutescens X Capsicum annuum). Only three of the ten interspecific crosses germinated. Reciprocal crosses: Capsicum annuum X Capsicum frutescens did not germinate. Effectively the total number of crosses was reduced to twenty three. During experiment IV, F1 plants were raised along with their parents for evaluation of yield traits under field conditions with the application of plant protection chemicals and without application of plant protection chemicals for natural disease incidence screening. Vellayani Athulya was used as check variety. All the characters showed non-additive gene action except for fruit girth in the experiment with the application of plant protection chemicals. Highly significant gca effects for fruit weight, number of fruits per plant and yield were shown by the parents Venjaramoodu Local II (P1), IC-570376 (P6) and KD-2 (P2) respectively. High sca effect for number of fruits per plant and fruit yield per plant was shown by the cross combinations, AP-1(P4) x Unda Chilli (Vadakara Local) (P3) and KD-2 (P2) x Venjaramoodu Local II (P1) respectively. Based on mean performance and heterosis the cross combination IC 208580 (P5) x IC-570376 (P6) and Venjaramoodu Local II (P1) x KD-2 (P2) were found superior. Five cross combinations were identified for high yielding character under plant protected conditions while eight cross combinations showed tolerance to leaf curl- mosaic complex disease under natural field conditions. A total of five cross combinations were found to be superior to leaf curl mosaic disease tolerance and yield namely: IC-208580 (P5) x IC-570376 (P6), Venjaramoodu Local II (P1) x KD-2 (P2), KD-2 (P2) x Venjaramoodu Local II (P1), IC-570376 (P6) x KD-2 (P2) and KD-2 (P2) x IC-570376 (P6). The superior cross combinations selected for high yielding capacity along with tolerance to leaf curl-mosaic complex disease can be used in future breeding programs to develop superior high yielding and leaf curl mosaic complex tolerant chilli varieties.
Distant hybridization and compatibility studies in wild orchids
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Seeja, G; Arya, K
Genetic variability studies for yield and fruit fly resistance in bitter gourd (Momordica charantia L)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2010) Praveena, V S; Seeja, G
A study was undertaken in the Department of Plant Breeding and Genetics, College of Agriculture ,Vellayani during the period 2009-2010 to assess the genetic variability for different yield attributes and resistance to fruit fly in bitter gourd and to identify high yielding genotypes tolerant to fruit fly. To attain these objectives field and laboratory experiments were carried out simultaneously. Of the 29 genotypes evaluated IC-45341 was the early flowering and bearing type. Madhurai local was the genotype having maximum number of fruits per plant. Priya and Bharanikkavu local had maximum fruit length and girth respectively. Kanakakunnu local had maximum fruit weight and yield per plant. Kallukuthiavila local and Madhurai local were the long duration and short duration genotypes respectively. Priyanka had maximum protein content. Changanassery local -1 had maximum TSS, fruit colour and phenol content. IC- 68296 had maximum total sugars, reducing and non reducing sugars. Madhurai local had minimum incidence of fruit fly. Analysis of variance revealed significant differences for all the characters. Genotypic and phenotypic coefficients of variation were high for yield per plant, individual fruit weight, number of fruits per plant, fruit length, fruit girth, protein content, total sugars, reducing sugars, non reducing sugars, fruit colour, crude fibre content, phenol content and incidence of fruit fly. High heritability coupled with high genetic advance were noticed for all characters except days to first harvest, duration and water content which had high heritability and low genetic advance. Correlation studies revealed that out of the 13 significant phenotypic correlation coefficients of yield, twelve were positive and one was negative. Significant and positive correlations were obtained for yield with days to first male and female flower opening, days to first harvest, fruit bearing period, fruit length, fruit girth, individual fruit weight, duration, flesh thickness, incidence of fruit fly, protein content and water content. Significant negative correlations were obtained for incidence of fruit fly with phenol content and number of fruits per plant. Protein content, water content, phenol content and flesh thickness of immature, half mature and full mature fruits had significant correlation with incidence of fruit fly. Path coefficient analysis revealed high direct and positive effects of days to first male flower opening, fruit weight and duration on yield. D2 analysis grouped the 29 genotypes into seven clusters. Individual fruit weight contributed maximum to total divergence followed by flesh thickness, duration, fruit girth and protein content. High yielding genotype, Kanakakunnu local, was grouped into cluster I where as fruit fly resistant genotypes Madhurai local and Changanassery local – 1 were grouped into cluster V and VI respectively. This emphasizes scope for further improvement by selecting donor parents from these clusters. Selection indices revealed that Kanakakunnu local had maximum index value and Madhurai local had minimum index value. Kanakakunnu local, Changanassery local-1 and Madhurai local were identified as potent donors for appropriate breeding program for improving fruit yield and quality character like resistance to fruit fly. As per the techniques and rating system of Nath (1966) the percentage of fruit damage was minimum in Madhurai local and Changanassery local-1 under both natural screening and artificial screening. So these two genotypes were rated as resistant/highly resistant genotypes.
Heterosis and combining ability analysis to leaf curl virus in chilli
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2014) Darshan, S; Seeja, G
Seed characterization and standardization of in vito germination protocol in Vanda tessellata (Roxb.) Hook.ex G.Don.
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2023-03-16) Athira, Chandranath.; Seeja, G
Seed characterization and standardization of in vitro seed germination protocol in Rhynchostylis retusa (L.) Blume.
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2023-03-16) Akhila, Rajan; Seeja, G