Abstract

PASCUALIDES, AL  and  ATECA, NS. Germination and vigour of Crotalaria juncea L. (Fabaceae) seed morphotypes. Phyton (B. Aires) [online]. 2013, vol.82, n.2, pp.313-319. ISSN 1851-5657.

Crotalaria juncea L. (Fabaceae) is an annual herbaceous species native to India. Their seeds have polymorphism in the seed coat color and different seed sizes. Seeds were grouped according to their seed coat color into uniform (dark gray seeds) and variegated (brown mottled seeds), to evaluate the vigour of C. juncea seed morphotypes. They were also classified into small (< 5mm length) and big seeds (>5 mm length). The 1000 seed weight, germination percentage, length and seedling dry weight, electrical conductivity and field emergence were evaluated. The results showed that uniform seeds had greater weight than those variegated of the same size morphotype; although they produced longer seedlings, seedling dry weight was associated with seed size too. Both morphotypes of seed coat had high percentages of germination. However, uniform seeds presented lower electrical conductivity and greater field emergence percentage than those variegated. These differences reveal that the two morphotypes of seed coat color have different vigour, and that seed size had no effect by itself on the variables studied. The 1000 seed weight showed a positive correlation with the (1) hypocotyl radicular axis length (r=0.68**) and (2) seedling dry weight (r=0.75***). However, it showed a negative correlation with the electrical conductivity (r=-0.56**). Field emergence correlated with seedling both length and dry weight (r=0.67*** and r=0.66**, respectively). It is important to determine the proportion of variegated seeds in a representative sample of the seed lot to define the appropriate seeding density of C. juncea.

Keywords : Crotalaria juncea; Seed size; Seed coat color; Germination; Vigour.

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