Variation in drought susceptibility among closely related wheat lines

• Published in: Field crops research 1995, Vol.41 (3), p.147-153
• Main Authors: Lazar, M.D., Salisbury, C.D., Worrall, W.D.
• Format: Article
• Language: English
• Subjects: amelioration des plantes; Breeding; Drought; drought resistance; fitomejoramiento; genetic variation; plant breeding; resistance a la secheresse; resistencia a la sequia; Susceptibility index; Triticum aestivum; variacion genetica; variation genetique; Water stress; Wheat
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/0378-4290(95)00015-I

Drought resistance is a complex trait for which systematic improvement has been difficult. One means of simplifying analysis of such a trait is through examination of variability among closely related genotypes. Sister lines of wheat exhibiting significant variation for rainfed yield, irrigated yield, and a drought susceptibility index, S, were identified among derivatives of a backcross breeding program. Of seven sister lines compared in a 2-y field study at Bushland, Texas, three were found significantly less susceptible than a related cultivar, TAM-107, two were significantly more susceptible than TAM-107 and two were not distinguishable from TAM-107. Relatively small, but significant, variability was observed among the lines for developmental variables, including anthesis date, date of physiological maturity and length of the grain-filling period. No meaningful correlations could be established, however, between developmental variables and yield or susceptibility index. While some differences may exist among these lines in mechanism underlying relative drought susceptibility, lack of correlation with developmental variables indicates that this set of lines may be valuable in identifying useful drought resistance mechanisms in wheat.