Inheritance and nature of cold tolerance in tomato [electronic resource].

Includes references.

Interspecific crosses were made between three cultivars, i.e. Edkawi, Floradade and UC. 97-3, which belong to Lycopersicon esculentum, and LAI383, which belongs to Lycopenicon hirsutum, to study the inheritance and nature of cold tolerance. All obtained populations, P1, P2, F1, F2, Bc1 and Bc2 for all possible interspecific crosses were evaluated in a field experiment as individual plants. Genetic differences were detected among the different parental genotypes concerning foliage cold tolerance, fruit set percentage and total yield/plant. The inheritance of cold tolerance, fruit set percentage and total yield/plant was in quantitative pattern. The high level of cold tolerance was partial dominant over the low level. The low percentage fruit set under low temperature showed partial dominance over the high percentage of fruit set. Over dominance was observed for high yield/plant in the interspecific cross Uc. 97-3 X LAI383. The broad sense heritability estimates for foliage cold tolerance were 98.73%, 87.19% and 60.91% while the estimates of the narrow sense heritability were 75.560/0, 63.22% and 56.97% for the interspecific cresses Edkawi X LAI383, Floraclade X LAI383 and UC. 97-3 X LAI383, respectively. The minimum number of effective gene pairs controlling foliage cold tolerance, percentage of fruit set and total yield/plant under low temperature were 1-4,2-3 and 1-4 gene pairs, respectively. Significant positive correlation was detected between foliage cold tolerance and total yield I plant. However, foliage cold tolerance was negatively correlated with each of Earliness, fruit weight and fruit length in the interspecific crosses Edkawi X LAI383 and Floradade X LA1383. Highly significant positive correlations between foliage cold tolerance and chemical composition of plant foliage, i.e. chlorophyll a and b and total carotenoides as well as reducing, non-reducing and total sugars were detected. The combined effect of fruit weight, number of fruit/plant, fruit length and diameter was found to have highly significant correlation with total yield/plant under low temperature conditions. Key words: Interspecific, Broad and narrow heritability, Correlation, Tomato, Lycoperskon hybrids.

Summary in Arabic.

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