Influence of Chilling upon Seedling Development of Cotton

Abstract

Injury induced by low temperatures above freezing, commonly called chilling injury, occurs in many plant species. Several comprehensive reviews have been written including those of Belehradek (3), Vasil'yev (12), and Levitt (6). Various theories have been cited as to the type of injury caused by chilling. Sachs (10) suggested an upset in transpiration activity; Molisch (9) an accumulation of harmful toxins. Wilhelm (13) concluded that chilling death results from cell dehydration and protein exhaustion. Germination and subsequent seedling growth of cotton Gossypium hirsutum L., are inhibited or adversly influenced by temperatures below 150 (1, 4, 7). Arndt (2) reported slow but normal seedling growth at 18? and maximum seedling elongation at 30 to 33?. Sellschop and Salmon (11) studied the influence of chilling (2-11?) on cotton of several maturity levels. The influence of soil moisture level and salt concentration was included in these studies. The present study represents a portion of a broad investigation of the response of cotton plants to low temperature. It deals with seedling response as measured by growth rate, and morphological and anatomical changes following 2 types of chilling treatment; one applied at the beginning of germination, and the second, applied following initiation of germination at favorable temperatures.