A mixed model for the effects of single gene, polygenes and their interaction on quantitative traits. 2. The effects of the nor gene and polygenes on tomato fruit softness

Abstract

The effects of the nor gene, polygenes and their interaction on tomato fruit softness one (SF1) and nine (SF9) days after picking at "breaker" stage of ripening were studied using two experimental populations, each obtained from a different cross and comprised of F3 families derived from selfed heterozygous (nor/+) F2 plants. The results were analysed using a mixed model for a single gene, polygenes and their interaction. A multiplicative nor x polygenes interaction was detected for SF1, and it was included in the model by log transformation. The multiplicative coefficients of the nor effect on family means were 0-76, 1-07, 1-23, and 0-77, 106, 122 for nor/nor, nor/+, +1+, respectively, in population 1 and 2, each. "Net Polygenic Heritability" was estimated as 051 and 027 in two different populations. The corresponding multiplicative coefficients for SF9 were 0-62, 106 and 151 and 0-60, 107 and 156. After log transformation, a random nor X polygenes interaction was also found for SF9. It was concluded that a rather small experiment of the design used (13-21 families, 305-461 individuals) facilitated simultaneous detection of the effects of a single gene, polygenes and their interaction on quantitative traits, as well as characterization of the nature of the interaction. This provided better understanding of the genetic control, as well as improved estimates of genetic parameters than those obtained when lack of such interaction was assumed.

Transgressive segregation for fruit quality traits in a cross between exotic and mutant genotypes ofLycopersicon

“…These authors suggested that other factors in addition to firmness are likely to be involved in the increased shelf life. Elkind et al (1990) reported that the expected effect of the nor gene will be greater in a soft genetic background. However, overall extended shelf life might be obtained in fruit with another genetic background.…”

Estimating effects of a single gene and polygenes on quantitative traits from a diallel design

“…In many cases, the major gene genotypes can be inferred from pedigree data or recognized by morphological phenotype or biochemical methods. For example, the opaque-2 gene in maize, glandless gene in cotton, nor gene in tomato (affecting fruit firmness and Table 7 Predicted genetic effects and standard errors for copula duration, developmental time, and esterase 6 activity in D. melanogaster shelf time) (Elkind et al 1990), esterase 6 gene in D. melanogaster (Gilbert 1985a), and SNPs in coding and promoter regions. Some methods thereof used ANO-VA procedure as the statistical tool (e.g., Gilbert 1985a, b;Elkind and Cahaner 1986).…”

“…Examples of such situations are well reported, e.g., fruit softness in tomato (Elkind et al 1990), mating speed in Drosophila melanogaster (Gilbert 1985a), plant height in rice (Jiang et al 1994) and in wheat (Pinthus and Gale 1990), pest and disease resistance (vertical and horizontal resistance), and grain quality in maize (Vasal et al 1980), in rice (Kumar and Khush 1987;Mckenzie and Rutger 1983), and in barley (Tallberg 1982). For shedding light on gene expression and for making an efficient genetic improvement strategy, it is of fundamental significance to dissect phenotypic variation jointly affected by major genes and by polygenes according to corresponding constituent causes.…”

The new kid on the block: a dominant‐negative mutation of phototropin1 enhances carotenoid content in tomato fruits

“…At times, the influence of dominant‐negative mutation such as Nac‐Nor or dominant mutation Nr may vary in different genetic backgrounds (Elkind et al , 1990; Lanahan et al , 1994; Rodríguez et al , 2010; Wang et al , 2020). Such influence was not conspicuous for Nps1 *, as in two different genetic backgrounds it dominant‐negatively stimulated carotenoids.…”