Chlorophyll fluorescence and carbohydrate concentration as field selection traits for heat tolerant chickpea genotypes

Identification and Characterization of Contrasting Genotypes/Cultivars for Developing Heat Tolerance in Agricultural Crops: Current Status and Prospects

“…In another chickpea study, 56 genotypes were exposed to high temperatures in the field from the flowering stage to crop maturity (maximum temperatures 25-40 • C)-the tolerant genotypes (PUSA1103, PUSA1003, KWR108, BGM408, BG240, PG95333, JG14, BG) had higher Pn than the sensitive genotypes (ICC1882, PUSA372, PUSA2024) (Kumar et al, 2017). Similarly, the response of four chickpea genotypes to a natural temperature gradient in the field at the flowering stage identified two heat-tolerant genotypes (Acc#RR-3, Acc#7) with high P n and two heatsensitive genotypes (Acc#2, Acc#8) with lower P n ; these results were validated in a climate chamber experiment set at 30/25 • C and 35/30 • C (Makonya et al, 2019). Improvement of heat stress tolerance by stabilizing PSII system through introducing IbOr gene in transgenic potato (Goo et al, 2015), sweet potato (Kang et al, 2017), and in alfalfa (Wang et al, 2015) is worth mentioning.…”

“…In an earlier study on soybean genotype K03−2897, high-temperature stress (38/28 • C) for 14 days at the flowering stage significantly decreased leaf P n , due to anatomical and structural changes (increased thickness of palisade and spongy layers and lower epidermis) in cells and cell organelles, particularly damage to chloroplasts and mitochondria (Djanaguiraman and Prasad, 2010). Two heattolerant chickpea genotypes (Acc#RR-3, Acc#7) had higher P n than two heat-sensitive genotypes (Acc#2, Acc#8) at high temperature (35/30 • C), which may have been due to increased RuBisCo activity (Makonya et al, 2019). In another chickpea study, 56 genotypes were exposed to high temperatures in the field from the flowering stage to crop maturity (maximum temperatures 25-40 • C)-the tolerant genotypes (PUSA1103, PUSA1003, KWR108, BGM408, BG240, PG95333, JG14, BG) had higher Pn than the sensitive genotypes (ICC1882, PUSA372, PUSA2024) (Kumar et al, 2017).…”

“…The two tolerant genotypes had higher photosynthetic rates, starch, sucrose and grain yield than the sensitive genotypes at the warmer site. The observation revealed that chlorophyll fluorescence and leaf carbohydrates are suitable tools for selection of heat tolerant chickpea genotypes under field conditions (Makonya et al, 2019). Screening of 15 alfalfa (Medicago sativa L.) genotypes by exposing seedlings to 38/35 • C day/night for 7 days in a growth chamber identified Bara310SC (F v /F m 0.79) and WL712 (F v /F m < 0.79) as heat-tolerant and heat-sensitive cultivars, respectively (Wassie et al, 2019), showing that F v /F m is an effective tool for phenotyping contrasting genotypes for heat tolerance.…”

Chlorophyll Fluorescence, Photosynthesis and Growth of Tomato Plants as Affected by Long-Term Oxygen Root Zone Deprivation and Grafting

“…As a result, significant advances have been made in improving selection criteria in a multitude of crops. Chl fluorescence is a quantitative and qualitative indicator of light-dependent photosynthetic processes, which has been suggested as a screening method for heat tolerance in chickpeas [15] and durum wheat [16], for drought tolerance in barley [17] or for flooding tolerance in some leguminous and cereals crops [18]. The combined measurements of Chl fluorescence and leaf gas exchange have been exploited to describe the adaptability and plant-ageing pattern in subterranean clover genotypes exposed to shading strain [19].…”

Exogenous Selenium-Instigated Physiochemical Transformations Impart Terminal Heat Tolerance in Bt Cotton

“…Heat stress speeds up the activities of protochlorophyllide oxidoreductase which ultimately accelerates the biotransformation of protochlorophyllide to chlorophyllide (Makonya et al 2019). Hence, rate of degradation of chlorophyll overwhelms the rate of biosynthesis of chlorophyll and, therefore, causes early senescence in cotton (Hafeez et al 2018).…”