Variation in the salinity tolerance of strawberry clover (Trifolium fragiferum L.)

Abstract

Saline soils negatively affect plant growth, so there is a need to develop salt tolerant plant materials for rangeland uses. Five strawberry clover (Trifolium fragiferum L.) cultivars were compared to 95 plant introductions for tolerance to salinity during germination and greenhouse seedling growth. Mean tolerance of the cultivars to NaCl during germination did not differ significantly (p>0.05) from that of the introductions. Individual plant introduction accessions were superior to each of the cultivars in tolerance to NaCl during germination. Mean shoot dry weight, shoot height, and number of shoot branches of the cultivars were greater (p<0.05) than those of the plant introductions in both the control and saline irrigation treatments. Mean cultivar plant tolerance to salinity, as indicated by saline/control treatment ratios for shoot dry weight, shoot height, and number of branches, was not superior to that of the plant introductions. Germination tolerance to salinity was not correlated with plant growth in either saline or non-saline irrigation treatments. Ample genetic diversity is present within strawberry clover to permit development of cultivars with superior tolerance to salinity during seed germination. It will be more difficult to develop cultivars with superior plant growth in both saline and non-saline environments.