The effect of cytoplasm on cold hardiness in alloplasmic rye (Secale cereale L.) and triticale

Abstract

Many changes occur within the cytoplasm of plant cells during cold acclimation. However, the cause and effect relationship between cytoplasmic response to low temperature and the development of cold hardiness in cells has been difficult to determine. This study considered the importance of rye (Secale cereale L.) and wheat (Triticum aestivum L. and Triticum tauschii (Coss.) Schmal.) cytoplasmic effects in conditioning plant cold hardiness. The cold hardiness of octoploid triticale (× Triticosecale Wittmack) produced from hardy rye and nonhardy wheat was similar to that of the wheat parent, demonstrating a complete suppression of the rye cold hardiness genes. Similar observations were made for wheat – rye amphiploids from reciprocal crosses, indicating that this suppression was not due to cytoplasmic effects. It is more probable that, because the cold hardiness of octoploid triticale approximates that of the wheat parent, the cold hardiness potential of the rye genome is suppressed by a gene or genes in the wheat complement. The cold hardiness of alloplasmic rye with T. tauschii cytoplasm was similar to that of the rye parent indicating that the cold hardiness genes of rye have normal expression in the T. tauschii cytoplasm. Based on observations made in these two studies, it was concluded that the cytoplasm has little direct effect on cold hardiness, or on the nuclear expression of cold hardiness.Key words: cold hardiness, cytoplasm, Triticum aestivum L., triticale, alloplasmic rye.