| Author(s) | A. A. Alsadon, M. A. Wahb-allah and S. O. Khalil |
| Affiliation | Department of Plant Production, College of Food Sciences and Agriculture, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia |
| Title | In vitro Evaluation of Heat Stress Tolerance |
| Source | Journal of King Saud University. Agricultural Sciences. Volume 19, No 1. (2007/1427) |
| Abstract | Twenty locally grown tomato cultivars were evaluated for their in vitro heat tolerance. Leaf discs were collected during vegetative, flowering and fruiting stages and incubated in water bath at 40°C for 1, 2 and 3 hours. Electrical conductivity (EC) was measured as an indication of cell injury due to electrolytes leakage. The results indicated that cultivars can be classified into three groups according to their heat stress tolerance: (a): heat stress tolerant cultivars (EC ranged from 27.75 to 41.69 µmho/cm) which include Queen, Indian, Super Strain B, Pearson and Strain-B; (b): moderately heat stress tolerant cultivars (EC ranged from 43.80 to 50.70 µmho/cm). This group consisted of nine cultivars Pacmore, Tnshet Star, Rocky, Shohba, Raad VF, VFN-8, Moneymaker, Imperial and Pearson Imperoved; and (c): heat stress sensitive cultivars (EC ranged from 53.12 to 72.20 µmho/cm) and included Malica, Castle Rock, Edkawi, Chico, Pakmore VF and Super Marmand. Correlation coefficients among the three growth stages were positive and significant or highly significant which indicated that this method is effective in selecting genotypes at early growth stages. The incubation period of 2 hours was optimum for this test. This method is a useful tool for plant breeders to screen for heat stress tolerance of genotypes during early growth stages in breeding programs in addition to field evaluation in various agricultural production areas. |
