Impact of Heat Stress on Biochemical and Physiological Attributes of Thermotolerant and Thermosensitive Cucumber (Cucumis sativus L.) Genotype

Abstract

This research aimed to compare the growth, physio-biochemical, enzymatic, and yield aspects of one heat tolerant (Safoora F1-
Hybrid) and one heat sensitive genotypes (Cucumber Desi). These genotypes were exposed to two heat stress levels (23°C ±2day,
13°C ±2 night and 45°C±2 day and 35°C±2 night). Each pot contained four plants and there were five pots per replication. Ten pots
for each genotype were used and the total number of plants was eighty. After 45-day of sowing, heat-stress (45°C±2 day and
35°C±2 night) was applied. The heat-stress at (45°C±2 day and 35°C±2 night) was maintained till the end of the experiment. The
current study was laid out with two factors (Genotypes and Temperature) factorial under complete randomized design (CRD).
The maximum number of leaves (36, 20), shoot length (62.5 cm,37.37cm), shoot fresh weight (37.46 g, 32.94 g), shoot dry mass
(75.39 g, 47.64 g), leaf area (16.66 cm2 ,10.66 cm2), photosynthesis rate (14.55 μmol CO2 m-2 S-1, 5.23 μmol CO2 m-2 S-1) and the
number of fruits per plants (18, 10) were achieved in Safoora F1 hybrid and Cucumber desi at 23°C±2 as compared to 45°C±2
respectively. It was concluded that cucumber (both genotypes) showed higher growth, physio-biochemical, enzymatic, and yield
aspects when it is grown under 23°C±2 temperature as compared to 45°C±2. Safoora F1-Hybrid (Heat tolerant genotype) showed
maximum growth at 45°C±2 as compared to heat sensitive genotype (Cucumber Desi).