Germination,growth and yield responses of release d tomato (Solanum lycopersicum L.) Varieties to salt stress

Abstract

Tomato (SolanumlycopersicumL.)is the major horticultural crop and salinity is one of the major abiotic factors limitingits production and productivity in Ethiopia. High salt level of irrigation water may induce a reduction and delay of germination, growth, physiological activities and yield due to osmotic effect, nutrient imbalance and/or ion toxicity. The present study was conducted toassess germination, growth, physiological and yield responses of14 tomato varieties tosix different salinity levels. Evaluation of the varieties for salt tolerance was carried out in laboratory and greenhouse in 2018/19. Each treatment was replicated three times and arranged in RCBD in factorial arrangement. Germination percentage, germination index and seedling vigor, leaf number, leaf area, plant height, fruit yield, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, root to shoot ratio and photosynthetic rate were measured. All the traits showed significantdecrease (P<0.0001) with increased salt concentration,for except leaf number and root to shoot ratio. The result clearly revealed that the highest germination percentage (95%) was recorded from the control treatment for variety ARP, whilethe lowest germination percentage (11.67%) was recorded from 5dSm-1for variety Eshet. The highest shoot fresh weight (163.13g/plant), shoot dry matter (32.8g/plant) and leaf area (26.93 cm2) were recorded for the control treatment and the highest root fresh weight (12.27g/plant), root dry weight (5.53g/plant) and fruit yield (22.71ton/ha) were recorded at 1dSm-1for variety Melka Shola, while the lowest shoot fresh weight (79.9g/plant), shoot dry matter(22.67g/plant),leaf area(17.63 cm2),root fresh weight (6.12g/plant) and root dry weight (3.8g/plant) were recorded at 5 dSm-1 for variety ARP. The lowest yield (16.73qt/ha) was recorded at 5 dSm-1 for variety ARP. The highest and the lowest values of photosynthetic rate (0.82µmolCo2m-2s-1 and (0.47 µmolCo2m-2s-1respectively) were obtained from the control treatment and the highest salinity level for variety Melka Shola, whereas, corresponding values of (0.84µmolCo2m-2s-1 and 0.56µmolCo2m-2s-1 were recorded for variety ARP. Results of laboratory analysis showed that, sodium and Na/K significantly increased with increased salinity level. However, potassium, Sulfur and phosphorus showed significant decrease with increasing salinity level. Among the varieties. MelkaShola wasfound to be more salt tolerant.Since the present experiment was conducted for one season and under controlled condition,it deserves further evaluation and verification under field condition in salt affected areas and the effect of salinity on tomato quality also deserves further investigation.