Morphological analyses of spring wheat (CIMMYT cv. PCYT-10) somaclones

Abstract

The objectives of this study were to induce callus from single immature wheat embryos, produce multiple seedlings from the induced callus, and analyse the somaclonal regenerants for potential grain production in a space garden. Immature wheat, Triticum aestivum L. (cv. PCYT-10), embryos were excised 10 to 12 days post-anthesis and cultured on modified Murashige & Skoog's inorganic salts. Embryos cultured on medium containing kinetin (6-furfurylaminopurine) at 0.5mgl -~ plus 2 or 3mgl -~ dicamba (1-methoxy-3,6-dichlorobenzoic acid) or 0.2mg 1 -~ 2,4-dichlorophenoxyacetic acid produced calli from which 24, 35 and 39% of the explant tissue exhibited regenerants, respectively. The size of flag leaves, plant heights, tillers per plant, spike lengths, awn lengths, and seeds per spike were significantly different in regenerants of two-selfed recurrent generations (SC~, SC2) than in parental controls. However, there were no significant differences in spikelets per spike between the SC: and parental controls. Desirable characteristics that were obtained included longer spikes, more seeds per spike, supernumerary spikelets, and larger flag leaves, variants that should be useful in wheat improvement programs.

AFLP analysis to assess genomic stability in Solanum regenerants derived from wild and cultivated species

“…In Solanum, various authors have reported that somaclonal variation affects noteworthy traits such as resistance to tuber soft rot and root-knot nematodes (Taylor et al 1993;Grammatikaki et al 1999), nutrition quality (Langille et al 1998) and agronomic traits (Thieme and Griess 1996). Despite the great plasticity of the potato genome (Hasim et al 1990;Abe et al 1999;Jain 2001), we did not observe shifts in terms of resistance to late blight in any of the regenerated plants tested (data not shown), and all genotypes showed the same high resistance level as their parents, revealing for this trait a ''silent nature'' of the changes observed. However, some gene changes might not have been observed at a morphological or physiological level because the structural differences in the gene product may not have altered its biological activity sufficiently to result in a modified phenotype.…”