Heterosis in Tomato (Solanum lycopersicum L.) for Yield and Yield Component Traits

Abstract

Estimates of heterosis for F1 hybrids over mid and better parent were computed for traits that showed significant differences between genotypes on analysis of variance. Heterosis for yield components and yield was studied using 8x8 half diallel cross in tomato (Solanum lycopersicum L.). The heterosis for yield was generally accompanied by heterosis for yield components. Heterosis for marketable fruit yield per plant ranged from (-63.4%) (P3xP8) to (33.8%) (P6xP8) and (-62.5%) (P3xP8) to (52.6%) (P5xP7), for mid parent and better parent respectively. Significant heterosis over better and mid-parent was observed for all the traits. Best parent and Mid-parent heterosis (MPH) was highest and in desirable direction for number of marketable fruit per plant (29.3%; 29.2%) in crosses ( P3xP6 for both ) and pericarp thickness (46.3%; 57.6%) in crosses (P2xP6 and P4xP8), number of fruit cluster per plant (32.8%; 35.9%) in cross (P3xP6 for both), individual fruit weight (36.1%; 41.2%) in cross (P2xP8, P3xP5) and fruit diameter (28.4%; 28.3%) in cross (P3xP5; P2xP6), fruit length (23.07%; 20.4%) in cross (P2xP6 for both). Out of 28 F1 crosses, positive and desirable heterosis by 10 crosses over better parent and 17 crosses over mid-parent were observed for total fruit density in tomato. An important heterosis both in heterobeltiosis and mid-parent was recorded in marketable fruit yield in ton per hectare. From all the crosses, seven crosses revealed positive from which three crosses are the most important P2xP7 (31%), P3xP5 (20%) and P3xP6 (54%) in better parent heterosis. Similarly for mid-parent heterosis, only ten crosses out of 28 reveled positive while the rest 18 crosses showed the undesirable direction for marketable fruit yield indicating majority of the hybrids exhibited unfavorable heterotic response and only a few hybrids could be considered for selection.

Impact evaluation combining ability of tomato hybrids and lines for production and fruit quality traits

“…Combining ability is an effective tool, which gives useful genetic information for the choice of parents in terms of performance of their hybrids, providing valuable insights for improving yield and quality traits for tomatoes (Hamdi, 2022) and a low value indicates weak host variation (Solieman et al, 2013) which is inconsistent with the results of this study. These results imply that both additive and no additive gene effects work together to impact characteristics, with the additive effects of genes playing a dominant role in trait inheritance (Soresa et al, 2020). In Griffing's method 2, variances due to GCA and SCA effects were significant for all traits.…”

Evaluation of F2 Tomato Hybrids for Yield and Related Traits in Jima Geneti District, Western Ethiopia

“…According to [13], broad sense heritability was calculated using a method proposed by [14] and [16]. We evaluated the projected genetic progress for several traits under selection using the method proposed by [15] and [4]. The formulas proposed by [14] and [15] were used to calculate the genotypic and phenotypic correlation coe cient for every conceivable combination.…”

“…In terms of acreage, productivity, industrial uses, and contribution to human nourishment, it has grown to be a signi cant commercial crop. Due to its diploid, relatively compact, newly sequenced genome, and abundance of genetic and genomic resources, the tomato has unique qualities that make it a commercially signi cant crop, the world's rst vegetable in production, and a model plant species [4]. Because of its high yield per plot area, ease of preparation for consumption, quick maturation time, low water requirements, and other proven bene ts, tomatoes are known to be used most frequently.…”

Combining ability for morphological and nutritional traits in a diallel cross of tomato (Solanum lycopersicum L.)

“…In Nigeria, there is still a significant gap in the development of high yielding and nutritive tomato hybrids. Several biotic and abiotic stresses are major impediments to the successful adoption and cultivation of improved tomato varieties (Soresa et al, 2020). The Nigerian tomato market is currently saturated with mixtures of diverse cultivar that are unable to meet the numerous demands.…”