Effect of seed germination methods on seedling emergence and earliness of purslane (Portulaca oleracea L.) cultivars in a hydroponic floating system.

摘要

The effects of different seed germination methods on the timing of seedling emergence and earliness of cultivars of purslane (P. oleracea) cultivated in a floating system were studied. Seeds were sown directly into Styrofloat trays containing vermiculite. Seeds were obtained from cultivars Golden Purslane and Summer Purslane (commercial seeds), and local accessions 01-215 and 0-294. The following germination methods were tested: (T1) pre-germination treatment for one day in a germination chamber at 25 degrees C and 95% relative humidity, (T2) pre-germination treatment for one day in a germination chamber at 25 degrees C and 65% relative humidity, and (T3) trays directly transferred to flotation beds and maintained floating permanently on fresh tap water. Seedlings were grown in the floating system for 16 days. At 2 days after sowing (DAS), germination methods T1 and T2, and commercial seeds, resulted in a higher percentage of emerging seedlings than method T3 and local accessions seeds, respectively. Commercial seeds germinated in T2 showed the highest final percentage of emergence. T1 and T2 methods, and commercial seeds, resulted in a higher emergence index than T3 and local accessions, respectively. Significant interactions between the germination method and cultivar were evident for the degree of emergence and germination index. Earliness, measured as the number of developed pairs of leaves of purslane at harvesting (17 DAS), was not affected by any of the germination method, but was cultivar-dependent. In general, germination methods T1 and T2, and commercial seeds, increased purslane seedling emergence in the floating system, but did not affect earliness.