INFLUENCE OF TEMPERATURE ON STERILITY OF TWO CYTOPLASMIC MALE-STERILITY SYSTEMS IN RAPE (Brassica napus L.)

Abstract

The effect of temperature on two cytoplasmic male-sterility (CMS) systems in rape (Brassica napus L.) was investigated. These were the nap CMS system with cytoplasm which occurs in most Canadian cultivars and the pol CMS system with cytoplasm from the cultivar Polima. The day/night temperature regimes used were 22/16, 26/20 and 30/24 °C. Two floral characteristics, anther type and stamen length, were influenced by temperature treatments. Male sterility of both CMS systems was expressed consistently at the lowest temperature. The nap male-sterile plants became partially sterile at the second temperature and fully fertile at the highest temperature. The pol male-sterile plants were more stable and became partially sterile only at the highest temperature.Key words: Rape, Brassica napus L., CMS, temperature