Resumo

IXTAINA, VY  e  MUJICA, MM. Variability in seedling vigor components of Lotus tenuis according to planting date and seeding density. Phyton (B. Aires) [online]. 2010, vol.79, n.1, pp.95-100. ISSN 1851-5657.

The slow initial growth of Lotus tenuis limits its use to improve the Flooding Pampas grasslands by mean of its intersowing. Research on the inter and intra-population variability of seedling vigor under changing environmental conditions, and the population x environment interaction, contribute to design sowing strategies and selection criteria. The objective of this study was to evaluate the inter and intra-population phenotypic variability, under different plant densities and planting dates. Variables measured included the number of stems (Nt), and the shoot dry weight (PSa) in L. tenuis seedlings. Crown stems and PSa were determined in 5 populations in a completely randomized design with 3 replicates (pots). Two sowing times (winter and spring) and two densities (25 and 50 seedlings/pot) were investigated. Multifactor ANOVA, Tukey test and linear regression analysis were applied. The intra-population variability was analyzed for the spring sowing at the highest seeding density. It was done by taking the average, minimum, maximum and coefficient of variation as measurement parameters. Population effects and population x environment interaction were found for both seedling characters in winter. However, only the density effect was significant in spring. From the whole analysis, only the population and density effects were distinguished for both characters. The intrapopulation variability was wide for PSa and narrow for Nt. Linear regression analyses showed that the variation of PSa was highly explained by Nt (R2= 62.30%).

Palavras-chave : Lotus tenuis; Seedling vigor; Plant densities; Planting date.

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