Variety traits
Heat tolerance is a plant's genetic ability to maintain metabolic activity and productivity under high temperature conditions. It manifests as resistance to protein denaturation, turgor loss, and generative organ mortality.
Mentioned in descriptions 1 598 varieties reference book.
Heat tolerance is a genetically determined ability of plants to withstand high air and soil temperatures without significant damage to development and yield. When critical values, typically ranging from 35–40 °C, are exceeded, processes of protein denaturation and cell membrane degradation begin in plant tissues. Externally, this manifests as wilting, the appearance of heat scorch, flower/fruit abscission, and pollen mortality, leading to significant yield losses and sterility.
This trait is not static and changes during plant ontogeny: the seedling and flowering stages are considered the most vulnerable to overheating. Variety resistance is ensured by two key strategies: an overheating avoidance mechanism based on intensive transpiration via a well-developed root system, and physiological endurance. The latter includes the ability of cells to retain bound water, increased cytoplasm viscosity, and the active synthesis of specialized heat-shock proteins/enzymes.
Evaluation of variety heat tolerance is carried out using laboratory climate chambers or field express-methods, measuring the degree of tissue browning, chlorophyll fluorescence, or proline concentration in cells as a stress marker. Varieties with high heat tolerance are capable of consistent fruiting at temperatures of 35–40 °C and above, whereas low tolerance leads to functional inhibition as early as 30–35 °C. A temperature of 50 °C is considered the critical threshold for most agricultural crops, leading to cell death.
Selection based on the description text, not official resistance ratings: such data is not available in registers. Mention indicates that the trait is discussed in the variety's sources; see the variety's profile for details on what is specifically stated.
Brassica oleracea L. (White Cabbage Group) · White cabbage
REED SEED (US)
Brassica oleracea L. (Brussels Sprouts Group) · Brussels sprouts
Takii & Co. Ltd., Kyoto 600-91
Zea mays L. · Maize
PIONEER OVERSEAS CORPORATION
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
Helianthus annuus L. · Sunflower
Remy ROUANET
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Capsicum annuum L. · Bell pepper
ZKI, H
Brassica oleracea L. (Broccoli Group) · Broccoli
Sakata Seed Corporation, JP
Cucurbita pepo L. · Field pumpkin
Paul Degreef
Citrullus lanatus (Thunb.) Matsum. & Nakai · Watermelon
Nunhems B.V.
Brassica oleracea L. (Cauliflower Group) · Cauliflower
SSC JP
Festuca arundinacea Schreb. · Tall fescue
DLF Pickseed USA
Capsicum annuum L. · Bell pepper
Sakata Vegetables Europe S.A.S
Solanum tuberosum L. · Potato
Station de Recherche du Comité Nord G.I.E.
Poa pratensis L. · Kentucky bluegrass
Rutgers, The State University of New Jersey
Agrostis stolonifera L. · Creeping bentgrass
PURE SEED TESTING
Cucurbita pepo L. · Field pumpkin
SEMILLAS FITO, S.A.
Brassica rapa L. subsp. pekinensis (Lour.) Hanelt · Napa cabbage
SSC JP
Festuca arundinacea Schreb. · Tall fescue
FAL Station de Recherche Agronomique Federale (CH)
Lactuca sativa L. · Lettuce
The State of Israel - Ministry of Agriculture and Rural Development - Agricultural Research Organization (ARO)^^^Hazera (1939) Ltd.
Cucumis sativus L. · Cucumber
MONSANTO HOLLAND B.V. (NL)
Agrostis stolonifera L. · Creeping bentgrass
Rutgers, The State University of New Jersey
Trifolium repens L. · White clover
DLF-TRIFOLIUM DANSK PLANTEFORAEDLING
Festuca arundinacea Schreb. · Tall fescue
Rutgers, The State University of New Jersey and Jacklin Seed by Simplot