Regenerative trait and cold hardiness in highly productive cultivars of alfalfa and red clover

Abstract

In earlier work on improvement of persistance in forage legumes, we selected genotypes from highly productive cultivars of alfalfa, Algonquin and Apica (Euphytica 45: 105-112, 1990) and cv. Florex red clover (Plant Cell Reports 8: 395-398, 1989) capable of in vitro regeneration from callus and cell culture. The alfalfa germplasm and its F1 progeny as well as an F2 red clover population were tested for cold stress tolerance. Plantlets were hardened in culture tubes at 2 or 5 ° C, 8 h photoperiod, for at least four weeks and then subjected to freezing temperatures, -16 or -10°C for alfalfa and red clover, respectively. Survival of regenerative genotypes was significantly higher than of the non-regenerative ones in both species. A strong positive correlation (r = 0.78) between the regenerative trait and plant survival was found in alfalfa. The experiments indicate that in vitro selection for regenerative trait may improve cold stress tolerance of alfalfa and red clover.

A cold-induced gene from Medicago sativa encodes a bimodular protein similar to developmentally regulated proteins

“…The amino acid identity is especially high (68 ~o) between the hydrophobic segment of m s a C I C and that of Dar215g [1], a cDNA clone specifically expressed during somatic embryogenesis in carrot cell suspension culture. The similarity between MSACIC and proteins that are expressed during embryogenesis in carrot [1] and maize [8] is particularly intriguing in the light of results obtained by Nowak et al [19] showing that in vitro regenerability and winter hardiness are traits that are closely related in alfalfa. According to these authors, this relationship could be due to a linkage between genes responsible for in vitro regenerability and those required to survive frost.…”

Somaclonal Variation and Induced Mutations in Crop Improvement

“…Cold hardiness (-10°C) T. aestivum Miller et al , 1992;Duncan et al, 1991bOjima and Ohira, 1982Conner and Meredith, 1985a,b Okawara et al, 1986Bouharmount, 1994Nunez et al , 1985Wersuhn et al, 1988,b Jackson et al, 1984Huang and Goldsbourgh, 1988Li and Chen, 1987Kishor and Reddy, 1986Hsissou and Bouharmont, 1994Lu et al, 1989Sears et al, 1992Trolinder and Shang, 1991Ezura et al, 1995O'Connor et al, 1991Nowak et al, 1992Bouharmont, 1994Nowak et al, 1992Dörffling et al, 1993…”

Morphological and agronomic characteristics of Croatian red clover (Trifolium pratenseL.) breeding populations tolerant to abiotic stress

“…Tolerance of field crop to abiotic stress, such as drought and cold tolerance (Peter et al, 2006;Pepo et al, 2006;Czıvek et al, 2006) is of primary importance for sustainable crop production in stress environment. Tolerance to abiotic stresses in red clover was analysed in few studies (Nowak et al, 1992;Nelke et al, 1999). Red clover is the most important fodder crop in north-western region of Croatia where climate is humid, soils shallow and wet, and vegetation period short (Gagro, 1998).…”