TABLE 1.
Few selective heat-tolerant genotypes identified for various crops involving various traits (details in the text).
| Crop | Traits used | Screening method | Promising heat-tolerant genotypes | Country | References |
| 1. Cereals | |||||
| Barley (Hordeum vulgare L.) | Stay green trait | Field experiments (> 40°C) | L6 and L8 and L3 and L10 | Iran | Bavei et al., 2011 |
| Chlorophyll fluorescence | Growth chamber (45°C) | Ig, Im, and Tz | North Africa | Oukarroum et al., 2016 | |
| Wheat (Tritium aestivum L.) | Stay green trait | Field experiments (32°C) | CB367(BB#2/PT//CC/INIA/3/ALD“S,” CB = 333(WL711/3/KAL/BB//ALD“S”and CB335(WL711/CROW“S”//ALD#1/CMH7 7A.917/3/HI666PVN“S”) | Pakistan | Rehman et al., 2009 |
| Canopy temperature depression | Field experiment (41°C) | HD 2932, HD 2864, HD 3095, HI 8703, HUW 234 | India | Saxena et al., 2016 | |
| Rice (Oryza sativa L.) | Pollen-based | Growth cabinets (35°C, 38°C) | N22 | United Kingdom | Jagadish et al., 2008 |
| Cell membrane thermostability | Phytotron (40°C) | F473 | America | Sanchez-Reinoso et al., 2014 | |
| Maize (Zea mays L.) | Plant height | Field experiments (>40°C) | DTPYC9F119 | India | Debnath et al., 2016 |
| Root system architecture | Growth chamber (37°C) | H16, CML444, SC-Malavi | United States | Trachsel et al., 2010 | |
| 2. Legumes | |||||
| Chickpea (Cicer arietinum) | Photosynthetic rate | Field environment (25 to 40°C) | Pusa 1103, Pusa 1003, KWR 108, BGM 408, BG 240, PG 95333, JG 14, BG | India | Kumar et al., 2017 |
| Cell membrane thermostability | Growth chamber (40–45°C) | ICCV07110, ICCV92944, ICC1205 | India | Kumar et al., 2013 | |
| Lentil (Lens culinaris Medik.) | Biomass Stomatal conductance Chlorophyll fluorescence Chlorophyll content Sucrose Oxidative stress and antioxidants | Field study (>32/20°C) | IG2507, IG3263, IG3745, IG4258, and FLIP2009 | India | Sita et al., 2017a |
| Cell membrane thermostability | Growth chamber (34°C) | FLIP2009, Ranjan, Moitree, 14-4-1, IC201710, IC208329 | India | Choudhury et al., 2012 | |
| Mungbean (Vigna radiata L.) | Pollen-based Biomass Chlorophyll fluorescence Oxidative stress and antioxidants | Field experiments (>40/28°C) | EC693357, EC693358, EC693369, Harsha, and ML 1299 | India | Sharma et al., 2016 |
| Common bean (Phaseolus vulgaris L.), | Chlorophyll fluorescence | Growth chamber (42°C) | Ranit and Nerine RS | Bulgaria | Petkova et al., 2007 |
| Seed weight Seed number | Field conditions (27/24°C, 30/27°C, and 33/30°C) | Brio, Carson, G122, HB1880, HT38, Venture | Switzerland | Rainey and Griffiths, 2005 | |
| Alfalfa (Medicago sativa) | Biomass Chlorophyll fluorescence Cell membrane thermostability | Greenhouse and growth incubators (38/35°C) | Bara310SC | China | Wassie et al., 2019 |
| Soybeans (Glycine max L. Merr.) | Photosynthetic rate | Field experiments (36.5–38.6°C) | IA3023 and KS4694 | United States | Djanaguiraman et al., 2019 |
| Metabolites | Lab experiments (36°C/24°C; 46/26°C) | PI587982A | South America | Chebrolu et al., 2016 | |
| Cowpea (Vigna unguiculate L. Walp) | Seed weight | Field studies (41/25°C) | H36, H8-9, DLS99 | United States | Ismail and Hall, 1999 |
| Seed number | Greenhouse conditions, (36/27°C) | B89-600 and TN88-63 | United States | Ehlers and Hall, 1998 | |
| 3. Oil seed crops | |||||
| Indian Mustard (Brassica juncea L) | Plant height | Field conditions (34°C) | BPR-538-10, NRCDR-2, RH-0216 | India | Chauhan et al., 2009 |
| Canola (Brassica napus) | Pollen-based | Field studies (10–35°C) | Kadore, ARC98007, NPZ0591RR, and DSV06200 | United States | Singh et al., 2008 |
| Root system architecture | Growth chamber (32°C) | Invigor 5440 | Canada | Wu et al., 2017 | |
| Peanut (Arachis hypogaea L.), | Carbon isotope discrimination | Polytunnels (40/28°C) | Spanish botanical type | United Kingdom | Craufurd et al., 1999 |
| Peanut (Arachis hypogea) | Heat shock proteins | Controlled environment (50°C) | ICGS 76, COC038, COC068, COC050, COC041 | United States | Selvaraj et al., 2011 |
| Cotton (Gossypium hirsutum L.) | Cell membrane thermostability | Field conditions (>44°C) | NIA-80, NIA-81, NIA-83, NIA-84, NIA-M-30, NIA-M31, NIA-HM-48, NIA-HM-327, NIA-H-32, NIA-HM-2-1, NIA-Bt1, NIA-Bt2, NIA-Perkh, CRIS-342, CRIS-134, NIAB-111 and check variety Sadori | Pakistan | Abro et al., 2015 |
| Chlorophyll fluorescence | Green house (30 and 40°C) | DP393, VH260 and DP 210 B2RF | Africa | Van der Westhuizen et al., 2020 | |
| 4. Vegetable crops | |||||
| Potato (Solanum tuberosum L.) | Heat shock proteins | Growth chamber (40°C) | Norchip, Desiree | Baltimore | Ahn et al., 2004 |
| Tomato (Solanum lycopersicum L.) | Pollen-based | Field conditions (39.24/24.42°C) | Pusa Sadabahar, FLA-7171, NDTVR-60 | Japan | Srivastava et al., 2012 |
| Sucrose | Growth chambers (31/25°C) or Greenhouses (32/26°C) | FLA 7516, Hazera 3018, Hazera 3042, and Saladate | Israel/United States | Firon et al., 2006 | |
| Cabbage (Brassica species) | Metabolites | Control environment (25–35°C) | Yoshin, Kenshin and full white | Japan | Hossain et al., 1995 |
| Cucumber (Cucumis sativus L.) | Cell membrane thermostability | Growth room (40/32°C) | L-3466, Desi Cucumber | Pakistan | Ali et al., 2019 |