GENETIC DIVERGENCE FOR YIELD, YIELD ATTRIBUTES AND SCREENING FOR FUSARIUM WILT RESISTANCE IN TOMATO (Solanum lycopersicum L.)
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Date
2019-07-19
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College of Horticulture, Rajendranagar, HYD-30
Abstract
The present investigation entitled “Genetic divergence for yield, yield attributes and screening for fusarium wilt resistance in tomato (Solanum lycopersicum L.)” was undertaken to estimate the genetic divergence, molecular diversity and screening for fusarium wilt resistance and to carry out yield component analysis through correlation and path analysis. Twenty three genotypes were sown in a Randomized Block Design with three replications during Kharif, 2018 at P.G Research block, College of Horticulture, Rajendranagar, Hyderabad.
The analysis of variance (ANOVA) of RBD revealed highly significant differences among the genotypes for all the fifteen characters studied. Wide range of variability was observed for average fruit weight (1236.05) followed by plant height (776.81) and number of fruits per plant (360.07) indicating the scope for selection of initial breeding material for further improvement.
The result of mean performance of twenty three genotypes for fifteen characters revealed that the genotype EC-620382 was the superior for yield and yield contributing characters i.e. fruit yield per plant (2.39 kg) and number of fruits per plant (58.43). The genotype EC-631379 was significantly superior for plant height (133.63) and number of primary branches per plant (8.13). The check variety Arka vikas was found to be early as observed from days to first flowering (29.31) and days to 50 % flowering (32.67). The genotype EC-620503 was found more in fruit length (5.34) and fruit width (5.94), whereas, more average fruit weight was found in EC-620427 (110.07). The genotype EC-620428 was found to be superior for ascorbic acid (36.25 mg/100g). The genotype EC-631379 was found to be superior for TSS (7.47 0Brix). Highest beta-carotene content was found in EC-620422 (2.16 mg/100g). For lycopene content, the highest value of (3.98 mg/100g) was found in EC-615055.
Mahalanobis D2 statistical analysis classified 23 genotypes into ten clusters and revealed that number of fruits per plant contributed maximum towards divergence followed by ascorbic acid content, lycopene content, TSS, beta-carotene, fruit yield per plant, number of primary branches per plant, fruit length, plant height and fruit width.
The inter cluster D2 values of the ten clusters revealed that highest inter cluster generalized distance (597.76) was between cluster X and VIII, while the lowest (67.39) was between cluster VI and cluster V. The genotypes of clusters showing high genetic divergence could be effectively utilized in heterosis breeding programme.
High heritability coupled with high genetic advance as per cent of mean indicates operation of additive gene action, which was observed in characters viz., plant height, number of primary branches per plant, number of fruits per plant, fruit length, fruit width, average fruit weight, fruit yield per plant, total soluble solids, ascorbic acid content, lycopene content and beta-carotene. In the present study, the high genetic variability observed for number of fruits per plant, average fruit weight, fruit yield per plant and number of primary branches and indicated the significance of these characters to be used for selecting superior genotypes.
From correlation studies, fruit yield per plant exhibited high, significant and positive association with plant height, number of primary branches per plant, number of fruits per plant, days to last fruit harvest, fruit length, fruit width, average fruit weight, ascorbic acid, total soluble solids and lycopene content indicating the importance of these traits in selection for yield. These characters should form selection criterion in breeding programmes. Direct selection based on these traits could result in simultaneous improvement of traits and fruit yield in tomato. The path coefficient analysis in the study revealed the improvement of yield by improving the characters i.e. days to last fruit harvest, number of fruits per plant, fruit width, average fruit weight, ascorbic acid, total soluble solids, lycopene content and beta-carotene, the genotypes which exhibited better performance for these characters can be used in further improvement of tomato.
A total of hundred (100) markers, out of which 95 SSR (Simple Sequence Repeats) and 5 gene specific markers were used to study molecular divergence of twenty three genotypes. Out of 95 SSR markers, 33 markers reported to be highly polymorphic with a total of 74 alleles. The results indicated significant genetic variation among 23 tomato genotypes studied. PIC value among the genotypes were varied from 0.28 (TEI-0396) to 0.76 ( TGS-633) with an average of 0.53. PIC of > 0.5 is highly informative for genetic studies.
Cluster analysis done using SSR revealed that Pusa ruby and EC- 620406 was found to be the most diverse. Hence, based on cluster analysis, the identified diverse tomato lines can be effectively selected for carrying out various breeding and crop improvement programmes.
Screening with Ty-1 (P6-6) marker, only one genotype i.e. AVTO-1219 showed resistant band. Screening with Ty-2 marker, only 2 genotypes viz., AVTO-1219 and AVTO-9804 showed resistant bands. Screening with Ty-1 (SSR 47) marker, 3 genotypes i.e. AVTO-1219, AVTO-9803 and AVTO-9804 showed resistant bands. Using Fw-Z 1063 marker,10 genotypes viz., EC-615055, EC-620428, AVTO-1219, EC-620378, EC-620389, EC-620394, EC-620422, EC-631369, EC-620503 and AVTO-9803 showed resistant bands. At molecular level, these ten genotypes showed resistant bands and these genotypes contain I-2 genes.
Screening for fusarium wilt resistance, among the twenty three genotypes, two were highly resistant i.e. AVTO-1219 and EC-631379, five genotypes were resistant, six genotypes were recorded moderately resistant, four genotypes were moderately susceptible over the highly susceptible check.
Considering the mean performance, five superior genotypes viz., EC-620382, EC-620428, EC-620463, EC-620427 and EC-631379 with high yield and quality components may be utilized as parents in further improvement studies through various breeding strategies and after multilocation, multiseasonal studies may be released. The genotype EC-620428 is with I-2 genes in addition to high yield. Hence, recommended for cultivation in fusarium wilt affected areas.
Description
The present investigation entitled “Genetic divergence for yield, yield attributes and screening for fusarium wilt resistance in tomato (Solanum lycopersicum L.)” was undertaken to estimate the genetic divergence, molecular diversity and screening for fusarium wilt resistance and to carry out yield component analysis through correlation and path analysis. Twenty three genotypes were sown in a Randomized Block Design with three replications during Kharif, 2018 at P.G Research block, College of Horticulture, Rajendranagar, Hyderabad.
The analysis of variance (ANOVA) of RBD revealed highly significant differences among the genotypes for all the fifteen characters studied. Wide range of variability was observed for average fruit weight (1236.05) followed by plant height (776.81) and number of fruits per plant (360.07) indicating the scope for selection of initial breeding material for further improvement.
The result of mean performance of twenty three genotypes for fifteen characters revealed that the genotype EC-620382 was the superior for yield and yield contributing characters i.e. fruit yield per plant (2.39 kg) and number of fruits per plant (58.43). The genotype EC-631379 was significantly superior for plant height (133.63) and number of primary branches per plant (8.13). The check variety Arka vikas was found to be early as observed from days to first flowering (29.31) and days to 50 % flowering (32.67). The genotype EC-620503 was found more in fruit length (5.34) and fruit width (5.94), whereas, more average fruit weight was found in EC-620427 (110.07). The genotype EC-620428 was found to be superior for ascorbic acid (36.25 mg/100g). The genotype EC-631379 was found to be superior for TSS (7.47 0Brix). Highest beta-carotene content was found in EC-620422 (2.16 mg/100g). For lycopene content, the highest value of (3.98 mg/100g) was found in EC-615055.
Mahalanobis D2 statistical analysis classified 23 genotypes into ten clusters and revealed that number of fruits per plant contributed maximum towards divergence followed by ascorbic acid content, lycopene content, TSS, beta-carotene, fruit yield per plant, number of primary branches per plant, fruit length, plant height and fruit width.
The inter cluster D2 values of the ten clusters revealed that highest inter cluster generalized distance (597.76) was between cluster X and VIII, while the lowest (67.39) was between cluster VI and cluster V. The genotypes of clusters showing high genetic divergence could be effectively utilized in heterosis breeding programme.
High heritability coupled with high genetic advance as per cent of mean indicates operation of additive gene action, which was observed in characters viz., plant height, number of primary branches per plant, number of fruits per plant, fruit length, fruit width, average fruit weight, fruit yield per plant, total soluble solids, ascorbic acid content, lycopene content and beta-carotene. In the present study, the high genetic variability observed for number of fruits per plant, average fruit weight, fruit yield per plant and number of primary branches and indicated the significance of these characters to be used for selecting superior genotypes.
From correlation studies, fruit yield per plant exhibited high, significant and positive association with plant height, number of primary branches per plant, number of fruits per plant, days to last fruit harvest, fruit length, fruit width, average fruit weight, ascorbic acid, total soluble solids and lycopene content indicating the importance of these traits in selection for yield. These characters should form selection criterion in breeding programmes. Direct selection based on these traits could result in simultaneous improvement of traits and fruit yield in tomato. The path coefficient analysis in the study revealed the improvement of yield by improving the characters i.e. days to last fruit harvest, number of fruits per plant, fruit width, average fruit weight, ascorbic acid, total soluble solids, lycopene content and beta-carotene, the genotypes which exhibited better performance for these characters can be used in further improvement of tomato.
A total of hundred (100) markers, out of which 95 SSR (Simple Sequence Repeats) and 5 gene specific markers were used to study molecular divergence of twenty three genotypes. Out of 95 SSR markers, 33 markers reported to be highly polymorphic with a total of 74 alleles. The results indicated significant genetic variation among 23 tomato genotypes studied. PIC value among the genotypes were varied from 0.28 (TEI-0396) to 0.76 ( TGS-633) with an average of 0.53. PIC of > 0.5 is highly informative for genetic studies.
Cluster analysis done using SSR revealed that Pusa ruby and EC- 620406 was found to be the most diverse. Hence, based on cluster analysis, the identified diverse tomato lines can be effectively selected for carrying out various breeding and crop improvement programmes.
Screening with Ty-1 (P6-6) marker, only one genotype i.e. AVTO-1219 showed resistant band. Screening with Ty-2 marker, only 2 genotypes viz., AVTO-1219 and AVTO-9804 showed resistant bands. Screening with Ty-1 (SSR 47) marker, 3 genotypes i.e. AVTO-1219, AVTO-9803 and AVTO-9804 showed resistant bands. Using Fw-Z 1063 marker,10 genotypes viz., EC-615055, EC-620428, AVTO-1219, EC-620378, EC-620389, EC-620394, EC-620422, EC-631369, EC-620503 and AVTO-9803 showed resistant bands. At molecular level, these ten genotypes showed resistant bands and these genotypes contain I-2 genes.
Screening for fusarium wilt resistance, among the twenty three genotypes, two were highly resistant i.e. AVTO-1219 and EC-631379, five genotypes were resistant, six genotypes were recorded moderately resistant, four genotypes were moderately susceptible over the highly susceptible check.
Considering the mean performance, five superior genotypes viz., EC-620382, EC-620428, EC-620463, EC-620427 and EC-631379 with high yield and quality components may be utilized as parents in further improvement studies through various breeding strategies and after multilocation, multiseasonal studies may be released. The genotype EC-620428 is with I-2 genes in addition to high yield. Hence, recommended for cultivation in fusarium wilt affected areas.
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Citation
Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad-30