Abstract
Guar (Cyamopsis tetragonoloba L. Taub.) being a summer annual legume is widely grown in some Asian countries primarily for three major purposes, i.e., cattle forage, as a green manure and for industry. Guar is relatively drought-tolerant compared to many other summer forages and it is well adapted to arid and semi-arid climates with high temperatures. We identified high-biomass-producing guar accessions in the hot, dry, and saline growth conditions of Saudi Arabia. We compared the performance of 24 introduced guar accessions as potential forage crop in Saudi Arabia, examining some key morphological traits and biomass production under water-limited and saline conditions in a greenhouse receiving natural sunlight and ambient temperature. The irrigation treatments were: 100% (Control), 80%, 60%, and 40% field capacity (FC), while salinity treatments were: Control (0 mM NaCI), 75 mM, 150 mM, and 200 mM NaCI. Accessions BWP 5595, 24320, Chiniot I, Chiniot 2, Kaloorkot 2, and BWP 5599 had higher fresh and dry biomass than that of BR-99, BR-90, 027340, 24333, 24332, Khanewal Local 2, and Bhawana 2; the former accessions were therefore considered drought-tolerant, while the latter drought-susceptible. Accessions 24320, BWP 5595, Chiniot 1, Chiniot 2, and 22159 were found to be more salt-tolerant than BWP 5589, 24333, Bhowana 2, 24287, 027340, and BWP5596. Overall, BWP 5595 and 24320 are drought- and salt-tolerant, respectively, while Khanewal Local 2 and BWP 5589 are drought-sensitive and salt-sensitive, respectively. Future guar breeding programs could use these germplasm resources to improve crops against conditions of drought, high salinity, and heat in Saudi Arabia.