Cold tolerance of forage plant species

• Published in: Semina. Ciências agrárias : revista cultural e científica da Universidade Estadual de Londrina Vol. 39; no. 4; pp. 1469 - 1476
• Main Authors: Manetti Filho, João, Oliveira, Carolina Maria Gaspar de, Caramori, Paulo Henrique, Nagashima, Getulio Takashi, Hernandez, Fernando Braz Tangerino
• Format: Journal Article
• Language: English
• Published: Universidade Estadual de Londrina 02.08.2018
• Subjects: Conductivity test; Fluorescence; Frost; Ion lixiviation; Low temperature
• ISSN: 1676-546X; 1679-0359
• DOI: 10.5433/1679-0359.2018v39n4p1469

The occurrence of frost in southern and southeastern Brazil affects pasture quality and limits the use of forage species with high yield potential. Therefore, elucidating the cold tolerance of individual forage species could facilitate the selection of species that will optimize production and animal feeding throughout the year. Accordingly, the aim of the present study was to evaluate the cold tolerance of forage species to low temperatures, based on cell membrane stability and photoinhibition. Alfalfa (Medicago sativa), sorghum (Sorghum bicolor), black oat (Avena strigosa), marandu grass (Urochloa brizantha), pearl millet (Pennisetum americanum), mombaça grass (Megathyrsus maximus), and bermuda grass ‘Tifton 85’ (Cynodon spp) plants were subjected to temperatures of 0.2, -0.9, -1.8, -2.7, -4.1, -4.6, and -6.2 °C for 1 h in a growth chamber. Cell membrane stability and photoinhibition were based on the electrical conductivity of leaf section solutions and chlorophyll fluorescence, respectively. Initial cold damage corresponded to a sudden increase in leaf solution conductivity and decrease in fluorescence. Millet and sorghum were able to tolerate exposure to temperatures as low as -2.7 °C, whereas black oat, marandu grass, alfafa, and mombaça grass were able to tolerate exposure to -4.1 °C, and bermuda grass ‘Tifton 85’ was able to withstand temperatures below -6.2 °C.