Growth and yield parameters as potential indicators of selection for moisture deficit tolerance in some Pakistani wheat (Triticum aestivum L.) cultivars

Abstract

The present study evaluated growth, yield and yield components of three wheat cultivars (Bhakher-2002, Inqalab-91 and Punjnad-2001) under varying degree of soil moisture deficit. The cultivars were grown under 60 and 20% soil moisture along with their control. Intensive moisture deficit induced more drastic (P< 0.001) effect on the performance of the cultivar as compared with moderate moisture deficit regime. Among the tested cultivar, Bhakher-2002 had better root and shoot growth under both moisture deficit situations. However, Punjnad-2001 excelled for germination, spike length, number of grains per spike and grain weight under moisture deficit environment. On the other hand, both growth and yield attributes appeared to be more prone in Inqalab-91 under moisture deficit conditions. The sensitivity of Bhakher-2002 and inqalab-91 can be attributable to insufficient gene pool of the cultivars which could not ensure their continued evolution and adaptation under prevalent stress conditions. Therefore, these two cultivars have not shown a threshold for moisture deficit. Conversely, the moisture stress tolerance in Punjnad-2001 may be manifestation of the occurrence of appropriate genetic variability for yield attributes within its existing gene pool which enabled the cultivar to evolve under strong selective pressures of increasing soil moisture deficit. Therefore, Punjnad-2001 can be recommended for molecular characterization to identify marker for drought tolerance. Key words: Wheat germplasm, selective pressure, soil moisture deficit, growth and yield.