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Gene action and gene expression analysis in yardlong bean(Vigna unguiculata ssp. sesquipedalis(L.) Verdcourt) for drought tolerance
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2022) Rahana, S N; KAU; Beena Thomas
Yard long bean (Vigna unguiculata ssp. sesquipedalis (L.) Verdcourt) is a highly remunerative legume vegetable of Kerala. Due to climate change and erratic rainfall, in summer season the crop growth and pod production is heavily affected by moisture stress. Development of high yielding varieties of yard long bean with drought tolerance is essential for its sustainable production. In this context, the present study entitled "Gene action and gene expression analysis in yard long bean (Vigna unguiculata ssp. sesquipedalis (L.) Verdcourt) for drought tolerance" was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, with an objective to identify drought tolerant genotype from the available germplasm and to understand the nature and magnitude of gene action and gene expression involved in the inheritance of drought tolerance in yard long bean. The study comprised four experiments. First experiment dealt with the seedling stage evaluation of 100-yard-long bean genotypes for drought tolerance in field. The moisture stress was imposed by withholding irrigation and later irrigation was restored in order to ensure the survival of the tolerant lines. The results of the analysis showed significant variations among genotypes. Out of the 100 genotypes screened, 15 drought tolerant genotypes were identified based on their better performance in terms of high RLW, low PWP, more number of days for reaching critical stress level and high recovery percentage. The genotypes identified were G1 (Acc 5), G5 (Acc 1339), G6 (Adoor local), G14 (Anchal local II) G15 (Aranmula local), G24 (Elamadu local), G36 (Kattampally local), G42 (Kollam local), G45 (Kottarakara local), G46 (Kottayam local), G50 (Kulashegarapuram local), 051 (Kulathupuzha local), G60 (Muttathukonam local), G74 (Nilamcl local) and G89 (Pongamoodu local). The fifteen selected genotypes from the first experiment were evaluated for drought tolerance in the second experiment by imposing moisture stress at the reproductive stage. Based on the biometric and physiological evaluations, the top seven genotypes with high yield and drought tolerance A4 (Anchal local II), A5 (Aranmula local), A7 (Kattampally local). All (Kulashegarapuram local), A13 (Muttathukonam local), A14 (Nilamel local), and A15 (Pongamoodu local) were selected as parents for further hybridization in experiment in. In the third experiment, LxT crosses were performed by using seven selected tolerant genotypes as lines with three popular yard long bean varieties as testers to generate twenty one hybrids. The genetic analysis of hybrids and parents were evaluated based on eight morphological and eight physiological parameters. Mean performance, combming ability, gene action and heterosis were estimated. Based on the mean performance and gca effects, L4 (Kulashegarapuram local) and L3 (Kattampally local) are identified as outstanding general combiners and can be exploited as parents for drought tolerance breeding in yard long bean. Three superior crosses, Kattampally local x Vellayani Jyothika (L3 x T3), Nilamel local X Lola (L6 X T2) and Kulashegarapuram local x Lola (L4 x T2) were identified as promising combinations for drought tolerance and yield xmder water stress. In the final experiment quantitative real time PCR was conducted to analyze the gene expression of drought responsive genes in tolerant hybrids and parents. The elevated expression of DREBs and NCEDl genes in tolerant hybrids and genotypes in gene expression analysis reflects the increased drought tolerance ability of those genotypes. The gene expression analysis was in conformity with the field studies. All the hybrids mamfested significant amount of dominance variance for commercial exploitation. Existence of significant amoimt of dominance variance and non-additive gene action suggests that hybridization as the best strategy for improving the drought tolerance character in yard long bean. The identified genotypes can be used for isolation of purelines with enhanced drought tolerance and the transgressive segregants from the identified crosses can be used for the development of drought tolerant high yielding cultivars in the fixture. The work can be continued with the identified genotypes and crosses for the development of climate smart drought tolerant varieties of yard long bean.
Open Access
Gene action and gene expression analysis in tomato (Solanum iycopersicum L.) under moisture stress
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2021) Chippy, A K; KAU; Beena, Thomas
The present investigation entitled ‘‘Gene action and gene expression analysis in tomato (Solanum lycopersicum L.) under moisture stress” was conducted during the period 2017-2021, in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Thirty-two genotypes including local genotypes of tomato were collected from different sources and studied under three different experiments. In the first experiment, twenty-one F1 hybrids derived from the line x tester mating and their ten parents were transplanted in the field and the treatment mean sum of square due to genotypes was found to be highly significant for all the characters studied which would ultimately indicate diverse nature of selected genotypes. The mean performance showed wide range of variation for most of the characters studied. Among lines, L7 (Pusa Ruby) showed higher mean performance for all-out of nine characters viz., plant height, fruit length, fruit girth, fruit volume, fruit weight, yield per plant, yield per plot, root length, root volume and relative water content. Among three testers, T2 (Kuttichal Local) showed favourable mean performance for seventeen traits viz., plant height, primary branches per plant, number of leaves per plant, number of flowering clusters per plant, number of fruits per cluster, fruit length, fruit girth, fruit volume, fruit weight, yield per plant, yield per plot, vitamin C, total acidity, stomatal frequency, root length, root volume and proline content. Under moisture stress (Second experiment), among the lines, L7 (Pusa Ruby) showed higher mean performance for eleven characters viz., plant height, fruit length, fruit girth, fruit volume, fruit weight, yield per plant, yield per plot, total soluble solids, root length, root volume and pollen viability. Among three testers, T2 (Kuttichal Local) showed favourable mean performance for sixteen traits viz., plant height, primary branches per plant, number of leaves per plant, number of flowering clusters per plant, number of fruits per cluster, number of fruits per plant, fruit length, fruit girth, fruit volume, total soluble solids, total acidity, stomatal frequency, root length, root volume and canopy temperature. Based on general combining ability analysis, the line L6 (Arka Alok) ranked as top by exhibiting significant gca effects for six traits viz., fruit length, fruit girth, fruit volume, fruit weight, specific leaf area and root length. Among the testers, T3 (Kottayam Local) had superior gca effects for Days to 50% flowering, number of flowering clusters per plant, number of fruits per cluster, fruit length, fruit volume, yield per plot, total soluble solids, lycopene, titrable acidity canopy temperature and proline content. Under moisture stress, the line L3 (Akshaya) ranked as top by exhibiting significant gca effects for ten traits viz., primary branches per plant, number of fruits per cluster, number of fruits per plant, fruit weight, yield per plant, yield per plot, stomatal frequency, specific leaf area, canopy temperature and pollen viability. Among the testers, T1 (Palakkad Local) had superior gca effects for plant height, number of fruits per cluster, number of fruits per plant, fruit girth, fruit volume, yield per plant, yield per plot, total soluble solids, relative water content, canopy temperature and proline content. In the case of hybrids, Based on mean performance, the crosses L1 x T1 (Vellayani Vijay x Palakkad Local), L2 x T3 (Anagha x Kottayam Local), L3 x T1 (Akshaya x Palakkad Local), L3 x T3 (Akshaya x Kottayam Local), L4 x T1 (PKM 1 x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T1 (Arka Meghali x Palakkad Local), L5 x T2 (Arka Meghali x Kuttichal Local), L5 x T3 (Arka Meghali x Kottayam Local), L6 x T2 (Arka Alok x Kuttichal Local) and L6 x T3 (Arka Alok x Kottayam Local) were superior for different yield characters. Under moisture stress, Hybrids L3 x T1 (Akshaya x Palakkad Local), L3 x T3 (Akshaya x Kottayam Local), L4 x T1 (PKM 1 x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T2 (Arka Meghali x Kuttichal Local), L7 x T2 (Pusa Ruby x Kuttichal Local) and L7 x T3 (Pusa Ruby x Kottayam Local) were superior for yield based on mean value. Based on combining ability studies under normal field condition, identified superior crosses such as L1 x T1 (Vellayani Vijay x Palakkad Local), L2 x T1 (Anagha x Palakkad Local), L2 x T3 (Anagha x Kottayam Local), L3 x T1 (Akshaya x Palakkad Local), L3 x T3 (Akshaya x Kottayam Local), L4 x T1 (PKM 1 x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L6 x T2 (Arka Alok x Kuttichal Local), L6 x T3 (Arka Alok x Kottayam Local), L7 x T1 (Pusa Ruby x Palakkad Local) and L7 x T3 (Pusa Ruby x Kottayam Local) exhibited higher sca effects for yield per plant. Under moisture stress, identified superior crosses such as L1 x T2 (Vellayani Vijay x Kuttichal Local), L2 x T3 (Anagha x Kottayam Local), L3 x T1 (Akshaya x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T2 (Arka Meghali x Kuttichal Local), L6 x T2 (Arka Alok x Kuttichal Local) and L7 x T3 (Pusa Ruby x Kottayam Local) exhibited higher sca effects for yield per plant. Based on heterosis, Overall, nineteen hybrids (L1 x T1, L1 x T2, L1 x T3, L2 x T1, L2 x T2, L2 x T3, L3 x T1, L3 x T3, L4 x T1, L4 x T2, L4 x T3, L5 x T1, L5 x T2, L5 x T3, L6 x T1, L6 x T2, L6 x T3, L7 x T1 and L7 x T3) from twenty one crosses revealed significant and positive heterobeltiosis for yield per plant under normal field condition. In the case of gene action, dominance genetic variance (σ2D) is higher than additive genetic variance (σ2A) was observed for all the traits under normal field condition and water stress condition, indicating that traits are controlled by non-additive gene action. Correlation study revealed yield per plant was positively and significantly correlated with the traits viz., primary branches per plant, number of flowering clusters per plant, number of fruits per cluster, number of fruits per plant, fruit girth, fruit volume, fruit weight and yield per plot. Based on qRT-PCR, the expression of both genes (moisture stress related genesSlDREB 1 and SlWRKY 4) was upregulated under water stress in all selected genotypes and the expression was more than moisture stress tolerant check variety. The result is in accordance with the analysis of moisture stress related physiological characters in these genotypes in the field under stress. From the study, identified tolerant sources for moisture stress viz., Akshaya, Pusa Ruby and Kuttichal Local, these lines and tester can be used in breeding programmes for moisture stress tolerance. Based on mean performance and gca, the genotypes Vellayani Vijay, Akshaya, Arka Meghali, Arka Alok and Kottayam local which showed superiority in yield and fruit quality traits can be used for breeding for improvement of yield and quality traits. The hybrids L3xT1 (Akshaya x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T2 (Arka Meghali x Kuttichal Local) and L7 x T3 (Pusa Ruby x Kottayam Local) which showed superiority for yield and quality characters with tolerance to moisture stress can be recommended for release after yield trials.
Open Access
Gene action and gene expression analysis in tomato (Solanum iycopersicum L.) under moisture stress
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2022) Chippy, A K; KAU; Beena, Thomas
The present investigation entitled ‘‘Gene action and gene expression analysis in tomato (Solanum lycopersicum L.) under moisture stress” was conducted during the period 2017-2021, in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Thirty-two genotypes including local genotypes of tomato were collected from different sources and studied under three different experiments. In the first experiment, twenty-one F1 hybrids derived from the line x tester mating and their ten parents were transplanted in the field and the treatment mean sum of square due to genotypes was found to be highly significant for all the characters studied which would ultimately indicate diverse nature of selected genotypes. The mean performance showed wide range of variation for most of the characters studied. Among lines, L7 (Pusa Ruby) showed higher mean performance for all-out of nine characters viz., plant height, fruit length, fruit girth, fruit volume, fruit weight, yield per plant, yield per plot, root length, root volume and relative water content. Among three testers, T2 (Kuttichal Local) showed favourable mean performance for seventeen traits viz., plant height, primary branches per plant, number of leaves per plant, number of flowering clusters per plant, number of fruits per cluster, fruit length, fruit girth, fruit volume, fruit weight, yield per plant, yield per plot, vitamin C, total acidity, stomatal frequency, root length, root volume and proline content. Under moisture stress (Second experiment), among the lines, L7 (Pusa Ruby) showed higher mean performance for eleven characters viz., plant height, fruit length, fruit girth, fruit volume, fruit weight, yield per plant, yield per plot, total soluble solids, root length, root volume and pollen viability. Among three testers, T2 (Kuttichal Local) showed favourable mean performance for sixteen traits viz., plant height, primary branches per plant, number of leaves per plant, number of flowering clusters per plant, number of fruits per cluster, number of fruits per plant, fruit length, fruit girth, fruit volume, total soluble solids, total acidity, stomatal frequency, root length, root volume and canopy temperature. Based on general combining ability analysis, the line L6 (Arka Alok) ranked as top by exhibiting significant gca effects for six traits viz., fruit length, fruit girth, fruit volume, fruit weight, specific leaf area and root length. Among the testers, T3 (Kottayam Local) had superior gca effects for Days to 50% flowering, number of flowering clusters per plant, number of fruits per cluster, fruit length, fruit volume, yield per plot, total soluble solids, lycopene, titrable acidity canopy temperature and proline content. Under moisture stress, the line L3 (Akshaya) ranked as top by exhibiting significant gca effects for ten traits viz., primary branches per plant, number of fruits per cluster, number of fruits per plant, fruit weight, yield per plant, yield per plot, stomatal frequency, specific leaf area, canopy temperature and pollen viability. Among the testers, T1 (Palakkad Local) had superior gca effects for plant height, number of fruits per cluster, number of fruits per plant, fruit girth, fruit volume, yield per plant, yield per plot, total soluble solids, relative water content, canopy temperature and proline content. In the case of hybrids, Based on mean performance, the crosses L1 x T1 (Vellayani Vijay x Palakkad Local), L2 x T3 (Anagha x Kottayam Local), L3 x T1 (Akshaya x Palakkad Local), L3 x T3 (Akshaya x Kottayam Local), L4 x T1 (PKM 1 x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T1 (Arka Meghali x Palakkad Local), L5 x T2 (Arka Meghali x Kuttichal Local), L5 x T3 (Arka Meghali x Kottayam Local), L6 x T2 (Arka Alok x Kuttichal Local) and L6 x T3 (Arka Alok x Kottayam Local) were superior for different yield characters. Under moisture stress, Hybrids L3 x T1 (Akshaya x Palakkad Local), L3 x T3 (Akshaya x Kottayam Local), L4 x T1 (PKM 1 x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T2 (Arka Meghali x Kuttichal Local), L7 x T2 (Pusa Ruby x Kuttichal Local) and L7 x T3 (Pusa Ruby x Kottayam Local) were superior for yield based on mean value. Based on combining ability studies under normal field condition, identified superior crosses such as L1 x T1 (Vellayani Vijay x Palakkad Local), L2 x T1 (Anagha x Palakkad Local), L2 x T3 (Anagha x Kottayam Local), L3 x T1 (Akshaya x Palakkad Local), L3 x T3 (Akshaya x Kottayam Local), L4 x T1 (PKM 1 x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L6 x T2 (Arka Alok x Kuttichal Local), L6 x T3 (Arka Alok x Kottayam Local), L7 x T1 (Pusa Ruby x Palakkad Local) and L7 x T3 (Pusa Ruby x Kottayam Local) exhibited higher sca effects for yield per plant. Under moisture stress, identified superior crosses such as L1 x T2 (Vellayani Vijay x Kuttichal Local), L2 x T3 (Anagha x Kottayam Local), L3 x T1 (Akshaya x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T2 (Arka Meghali x Kuttichal Local), L6 x T2 (Arka Alok x Kuttichal Local) and L7 x T3 (Pusa Ruby x Kottayam Local) exhibited higher sca effects for yield per plant. Based on heterosis, Overall, nineteen hybrids (L1 x T1, L1 x T2, L1 x T3, L2 x T1, L2 x T2, L2 x T3, L3 x T1, L3 x T3, L4 x T1, L4 x T2, L4 x T3, L5 x T1, L5 x T2, L5 x T3, L6 x T1, L6 x T2, L6 x T3, L7 x T1 and L7 x T3) from twenty one crosses revealed significant and positive heterobeltiosis for yield per plant under normal field condition. In the case of gene action, dominance genetic variance (σ2D) is higher than additive genetic variance (σ2A) was observed for all the traits under normal field condition and water stress condition, indicating that traits are controlled by non-additive gene action. Correlation study revealed yield per plant was positively and significantly correlated with the traits viz., primary branches per plant, number of flowering clusters per plant, number of fruits per cluster, number of fruits per plant, fruit girth, fruit volume, fruit weight and yield per plot. Based on qRT-PCR, the expression of both genes (moisture stress related genesSlDREB 1 and SlWRKY 4) was upregulated under water stress in all selected genotypes and the expression was more than moisture stress tolerant check variety. The result is in accordance with the analysis of moisture stress related physiological characters in these genotypes in the field under stress. From the study, identified tolerant sources for moisture stress viz., Akshaya, Pusa Ruby and Kuttichal Local, these lines and tester can be used in breeding programmes for moisture stress tolerance. Based on mean performance and gca, the genotypes Vellayani Vijay, Akshaya, Arka Meghali, Arka Alok and Kottayam local which showed superiority in yield and fruit quality traits can be used for breeding for improvement of yield and quality traits. The hybrids L3xT1 (Akshaya x Palakkad Local), L4 x T2 (PKM 1 x Kuttichal Local), L5 x T2 (Arka Meghali x Kuttichal Local) and L7 x T3 (Pusa Ruby x Kottayam Local) which showed superiority for yield and quality characters with tolerance to moisture stress can be recommended for release after yield trials.
Open Access
Breeding brinjal (Solanum melongena L.) for resistance to brinjal shoot and fruit borer
(Department of Plant Breeding and Genetics, College of Agriculture, Vellanikkara, 2021) Neeraja, Puthiamadom; KAU; Jiji, Joseph
Brinjal shoot and fruit borer is one of the most devastating pests of brinjal. It is a major bottle neck in the cultivation of egg plant. Identification of resistant sources and transfer of these genes into the high yielding varieties is an important step in mitigating the damage caused by this pest. Keeping the above facts in view, the present investigation entitled “Breeding brinjal (Solanum melongena L.) for resistance to brinjal shoot and fruit borer” was taken up in the Department of Plant Breeding and Genetics from Sept 2017- April 2021. Thirty one accessions belonging to eight different species of Solanum were evaluated in the field for resistance to brinjal shoot and fruit borer during Aug- Nov 2018. The treatments showed significant difference for all the characters studied. The highest number of primary branches was observed in IC618034 belonging to S. virginianum and the lowest number was observed in IC618035 belonging to Solanum melongena. Infestation of shoots by borer started nearly 7th week after transplanting. The number of damaged shoots was highest in Surya. The per cent shoot infestation ranged from 0 to 75 per cent. The wild accessions were resistant to brinjal shoot and fruit borer and only the melongena lines exhibited considerable damage. The extent of per cent fruit damage ranged from 0 per cent in the wild accessions to 64.67 per cent in Arka Neelkanth. Yield per plant and marketable yield per plant was highest in Vengeri. Based on the observation from the screening experiment conducted during August –November 2018, eleven accessions were evaluated further for a confirmatory screening during March- July 2020. As there was considerable infestation by borer, artificial inoculation was not carried out. There was significant difference among the treatments for the characters studied. Highest yield per plant and marketable yield per plant was observed in Vengeri. Lowest yield was observed in IC624241 and IC624239. Yield loss was highest in Ponni and lowest in IC624239. The resistance index developed by Mishra et al. (1988) was followed to classify the accessions. The accessions IC618035, IC618044, IC624241, Arka Kusumkar and Vengeri were graded as resistant (1-10 %) with respect to per cent shoot damage. Based on the extent the of fruit damage, the accessions IC618035, IC618044 and IC624239 and Arka Kusumkar were graded as moderately resistant (11-20%). IC624241 and Vengeri were graded as resistant (0-10%). Haritha, Surya, Arka Keshav, Ponni and Arka Neelkanth were graded as highly susceptible (>40 %). The biophysical, anatomical and biochemical basis of resistance was elucidated in the selected accessions. Trichomes in Solanum sps. were stellate in shape with six trichome strands forming one asterisk. Trichome density on calyx was negatively and significantly correlated with shoot damage while trichome density on leaf was positively and significantly correlated with shoot damage. Pericarp thickness, fruit breadth, total sugar content and total nitrogen content were positively and significantly correlated with per cent fruit damage. Total phenol content showed a significant negative correlation with the per cent fruit infestation. The resistant lines IC618035, IC618044, IC624241, Arka Kusumkar and Vengeri were characterized by thick epidermis and cuticle, dense and compact cortex and cambium, well developed vascular bundles and small pith. IC618044, IC624241, IC618035, Arka Kusumkar and Vengeri falling under the resistant and moderately resistant category were selected as testers to cross with highly susceptible lines Haritha, Ponni and Arka Neelkanth. The twelve hybrids and parents were screened in the field along with the hybrid ‘Neelima’ as check during Dec 2020- April 2021 to check the per cent infestation of brinjal shoot and fruit borer. On the basis of per cent fruit infestation the hybrids Haritha x JRPH IC624241 and Ponni x IC624241 were graded as immune. Haritha x IC618044, Haritha x IC618035, Ponni x IC618035 and Ponni x Vengeri were graded as resistant. The hybrids Haritha x Vengeri , Haritha x Arka Kusumkar, Ponni x IC618044 and Neelima were graded as moderately resistant. Ponni x Arka Kusumkar was graded as tolerant. The hybrid Arka Neelkanth x IC618035 Arka Neelkanth x IC618044 were graded as highly susceptible. L x T analysis revealed that Vengeri can be considered as a good combiner with respect to per cent shoot damage, yield per plant and marketable yield per plant. While Arka Kusumkar is a good combiner with respect to number of fruits per plant, number of damaged fruits and per cent fruit damage. Among the lines, Ponni can be considered as a good combiner in terms of yield and marketable yield. Ponni x Vengeri can be considered to be superior as it exhibited high positive heterosis over the mid parent, better parent as well as the commercial check for yield as well as marketable yield and high negative heterosis for per cent shoot and fruit damage. Almost all the hybrids exhibited negative heterosis for per cent shoot and fruit damage. Ponni x Vengeri was ranked as ‘one’ on the basis of organoleptic evaluation conducted with a panel of ten judges. DNA fingerprinting of the superior F1 hybrids and the respective parents done using nineteen ISSR markers revealed that Arka Neelkanth was unique in a way that it produced 10 bands for UBC 836. Comparing other hybrids highest number of bands for UBC 868, UBC 816, UBC 836 and ISSR 08 were produced by Arka Neelkanth. UBC 826 was used to identify bands common in hybrids and parents in Haritha x IC618044, Haritha x Arka Kusumkar, Ponni x Arka Kusumkar and Arka Neelkanth x IC618044. The bands similar in parents and hybrids were identified in all the hybrids except Ponni x IC624241. Superior hybrids viz., Ponni x Vengeri, Ponni x Arka Kusumkar and Haritha x Vengeri can be evaluated further. Mapping populations can be developed from the segregating generations to develop functional markers for resistance to brinjal fruit and shoot borer.

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