Vernalization Response of West Texas Wheat Varieties

Abstract

Vernalization, the conditioning of flowering response in plants by exposure to cold temperatures, can have a major impact upon crop productivity. For winter wheat (Triticum aestivum L.) grown in the southwestern Great Plains, correct response to vernalizing temperatures is critical in the development of new varieties, to assure that flowering and grain filling occur during the optimum time period. Ten winter wheat varieties commonly grown for grain production in West Texas were germinated and artificially vernalized at 40°F as seedlings at weekly intervals to provide vernalization periods ranging from 0 to 56 days. The seedlings were transplanted into pots in a winter greenhouse, and the days required to reach Feeke’s stage 6 (jointing) and Feeke’s stage 10.5 (anthesis) were counted for each plant. The experiment was performed in two successive years. All varieties were found to be responsive to vernalization; however, the patterns of response and ranking of varieties varied with vernalization time. Patterns of jointing response were generally similar, but not identical to patterns of anthesis response, with respect to vernalization time, for individual varieties. Ranking of varieties for either dependent variable at vernalization times of 42 or 49 days were consistent with the usual ranking of these varieties for developmental traits in field production in West Texas.