GENETIC DIVERGENCE FOR QUANTITATIVE AND QUALITATIVE TRAITS AND PEST POPULATION DYNAMICS IN RELATION TO WEATHER PARAMETERS IN CHERRY TOMATO (Solanum lycopersicum L.)
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Date
2019-07-16
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College of Horticulture, Rajendranagar, HYD-30
Abstract
The present investigation entitled “Genetic divergence for quantitative and qualitative traits and Pest population dynamics in relation to weather parameters in Cherry tomato (Solanum lycopersicum L.)” was undertaken to estimate the genetic divergence and to carry out yield component analysis through correlation, path analysis and pest population dynamics in relation to weather parameters. Twenty three genotypes were sown in a Randomized Block Design with three replications to evaluate genetic divergence. Single row with 7 plants of each genotype were sown to study pest population dynamics during Kharif, 2018 at College of Horticulture, Rajendranagar, Hyderabad, Telangana.
The analysis of variance (ANOVA) of RBD revealed highly significant differences among the genotypes for all the eighteen characters studied. Wide range of variability was observed for number of fruits per plant (32580.87) followed by average fruit weight (21276.17) and plant height (6264.61) showing the scope for selection of initial breeding material for further improvement.
The result of mean performance of twenty three genotypes for eighteen characters revealed that the check variety Swarnaratan was superior for yield and quality contributing characters i.e. fruit yield per plant (1.98 kg) and titrable
acidity (0.83 %) respectively. The genotype EC-313466 was found to be early as observed from the character days to first flowering (21.20 days) and days to 50% flowering (29.03 days). The genotype RHTC-2 was significantly superior for plant height (260.40 cm), number of fruits per plant (393.13), beta carotene content (2.39 mg/100g) and TSS (9.08 0Brix). The accession EC-514013 was found to be superior for number of primary branches (9.53) and lycopene content (3.85 mg/100g). The genotype EC-8014748 was found to be superior for days to last fruit harvest (135.93 days) and chlorophyll content (1.64 %). The accession EC-274046 was significantly superior for fruit width (4.64 cm) and average fruit weight (27.22 g).The genotype EC-251751 was found to be superior for anti-oxidant content (428.67 mg/100g). The genotype EC- 315479 was found to be early as in case of days to first fruit harvest (50.80 days). The accession RHTC-6 was found superior for fruit length (4.60 cm). Highest ascorbic acid was found in EC-631349 (49.64 mg/100g).
Mahalanobis D2 statistical analysis revealed that plant height contributed maximum towards divergence followed by average fruit weight, TSS, fruit yield per plant, number of fruits per plant, fruit length, lycopene content, ascorbic acid content and days to first flowering. The D2 analysis for eighteen characters partitioned the twenty three genotypes into five clusters. The inter cluster D2 values of the five clusters revealed that highest inter cluster generalized distance (462754.50) was between cluster III and V, while the lowest (58206.46) was between cluster III and cluster IV. The clusters indicating 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, days to first flowering, days to fifty per cent flowering, number of fruits per plant, fruit length, fruit width, average fruit weight, fruit yield per plant, anti – oxidant content, ascorbic acid content, lycopene content, beta- carotene, titrable acidity and chlorophyll content. In the present study, high PCV and GCV estimates were recorded for plant height, number of primary branches, number of fruits per plant, number of fruit per cluster, fruit length, fruit width, average fruit weight, fruit yield per plant, anti – oxidant content, ascorbic acid content, lycopene content, beta-carotene, titrable acidity and chlorophyll content indicating the existence of wider genetic variability for these genotypes.
From correlation studies, fruit yield per plant exhibited high significant positive association with fruit length, fruit width, average fruit weight, lycopene content and beta carotene indicating the importance of these traits in selection for
yield. Direct selection based on these traits would result in simultaneous improvement of afore said traits and yield per se in cherry tomato. The path coefficient analysis in the study revealed the improvement of yield by improving the characters i.e., days to fifty percent flowering, fruits per plant, average fruit weight and titable acidity. Yield per plant of tomato can also increase indirectly through number of primary branches, average fruit weight.
Considering the mean performance, five superior genotypes viz., for fruit yield Swarnaratan (1.98 Kg), RHTC-2 (1.67 Kg), EC-251751 (1.65 Kg), RHTC-6 (1.5 Kg) and RHTC-5 (1.24 Kg) may be released as pureline varieties after testing their stability over location and years for commercial cultivation. The genotypes with superior quality traits viz., EC-251751 for anti-oxidant content (428.67 %), EC-631349 for ascorbic acid (49.64 mg/100gm), EC-514013 for lycopene content (3.85 mg/100g), Swarnaratan for titrable acidity (0.83%), RHTC-2 for betacarotene (2.39 mg/100gm) and TSS (9.08 0Brix) and EC-801748 for chlorophyll content (1.64 %) can be included in pedigree selection for further improvement.
From correlation studies, whitefly infestation showed positive and significant association with sunshine hours in RHTC-6, RHTC-7, EC-163681 and EC-315479 and borer infestation was positive and significantly correlated with sunshine hours in RHTC-1, RHTC-2, RHTC-3, RHTC-5, Swarnaratan, RHTC-9, EC-274046, EC-801748, EC-514013, EC-251751 and EC-631349.
Screening of cherry tomato germplasm against whitefly as vector for leaf curl incidence revealed that RHTC-1, RHTC-2, RHTC-3, RHTC-4, RHTC-5, Swarnaratan RHTC-6, RHTC-7, RHTC-8, RHTC-9, RHTC-10, EC-251518, EC-801748, EC-514013, EC-211582, EC-315481, EC-631349 were found to be resistant and screening of borer resistance revealed that Swarnaratan, EC-211582, EC-315481, EC-631349 were found to be resistant. Hence, these identified varieties may be further confirmed for their resistance, then maybe exploited for resistance.
Description
Screening of cherry tomato germplasm against whitefly as vector for leaf curl incidence revealed that RHTC-1, RHTC-2, RHTC-3, RHTC-4, RHTC-5, Swarnaratan RHTC-6, RHTC-7, RHTC-8, RHTC-9, RHTC-10, EC-251518, EC-801748, EC-514013, EC-211582, EC-315481, EC-631349 were found to be resistant and screening of borer resistance revealed that Swarnaratan, EC-211582, EC-315481, EC-631349 were found to be resistant. Hence, these identified varieties may be further confirmed for their resistance, then maybe exploited for resistance.
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Citation
Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad-30