GENOTYPIC VARIATION IN THE RESPONSE TO SUB‐OPTIMAL TEMPERATURES OF GROWTH IN TOMATO (LYCOPERSICON ESCULENTUM MILL.)

Abstract

SUMMARYA growth analysis of plants raised under controlled environment conditions was used to examine the response to temperature of five contrasting tomato cultivars bred for outdoor production. Curves were fitted to the data of dry weight and leaf area and, to compensate for ontogenetic drift, instantaneous values of growth analysis parameters were calculated from these curves at a specific growth stage. Differences in relative growth rate which could be exploited in a breeding programme were not detected, though there were large differences in the components of relative growth rate. These were, however, compensatory within a cultivar. It was concluded that in order to select a genotype with improved growth rate it would be necessary to disrupt the compensation mechanism between the components of relative growth rate.

Growth analyses of tomato genotypes grown under low night temperatures and low light intensity

“…a high photosynthetic activity per unit leaf area or a large photosynthetic area. This was also observed in other genotypes of tomato by PAUL et al (1984). Genotype x temperature interactions.…”

“…Large differences between genotypes were found in total dry weight which have to be attributed to the differences in plant weight at the Euphytica 35 (1986) start of the experiments. From a growth analysis of five outdoor tomato genotypes, differing in cold tolerance, which were grown at a range of temperatures and a high light intensity, PAUL et al (1984) concluded that variation in seed weight is an important factor in the genotypic variation of plant weight. In the present experiments a positive correlation between seed weight and plant weight was only found in two of the three experiments.…”

Analysis of Stereochemical Convergence in Asymmetric Pd-Catalysed Allylic Alkylation Reactions Complicated by Halide and Memory Effects

“…As the environmental cultivation conditions were performed with only one cultivar, it could also be that using other cultivars might lead to significant differences in allergenic potential if grown under different conditions. However, this seems not very likely, because the variation in adaptability to environmental conditions is small among different tomato cultivars as a consequence of inbreeding during domestication 25, 26…”

Genetic Improvement of Tomato

“…Complex traits generally are of rather low heritability, more frequently because of excessive environmental effects than lack of genetic variation. Paul et al (1984) analyzed components of growth of five cultivars under controlled environments, but no differences in these components were useful in breeding. Bernier and Ferguson (1962) selected high-yielding, large-fruited tomato lines by focusing on early fruit set and the size of the first four ripe fruit.…”