Effect of temperature on pseudo-self-compatibility in Trifolium pratense L

Abstract

A relatively high temperature treatment, applied during anthesis, was shown to enhance self-seed production through pseudo-self-compatibility in normally self-incompatible red clover (Trifolium pratense L.). The self-seeds were produced in cultures of excised stems held in 2.5 percent sucrose. The stems were excised when petal color was beginning to appear in the buds. During anthesis the cultures were incubated with the flower heads at 40 ° and the stems at 25 °C. When most of the florets per head had opened the cultures were transferred to 20 °C and held at that temperature during the period of pollen growth through the styles and also during seed development. The addition of calcium nitrate and boric acid to the culture medium did not enhance anthesis, seed weight, or the number of seeds produced.Plant genotype and the environment provided before anthesis were the primary factors influencing the number of self-seed produced. Although not all attempts to produce self-seed have been successful, with repeated trials all clones we tested produced some seed.