Genetic Diversity Patterns in North American Public Soybean Cultivars based on Coefficient of Parentage

In the northern hemisphere, many species have been reported to have greater genetic diversity in southern populations than northern populations - ostensibly due to migration northward following the last glacial maximum (LGM). The generality of this pattern, while well-established for some taxa, remains unclear for North American trees. To address this issue, I collected published population genetics data for 73 North American tree species, and tested whether genetic diversity was associated with latitude or longitude and whether geographic trends were associated with dispersal traits, range or study characteristics. I found there were no general geographic patterns in genetic diversity, and the strength of the geographic gradients were not associated with any species or study characteristics. Species in the northern and western regions of North America tended to have more species with genetic diversity that declined with latitude, but most species had no significant trend. This work shows that North American trees have complex, individualistic, patterns of genetic diversity that may negate explanation by any particular dispersal trait or range characteristic.

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Genetic diversity in soybean seed quality under different storage conditions

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n1p57 ◽

2017 ◽

Vol 38 (1) ◽

pp. 57

Author(s):

Daniele Piano Rosa ◽

Danúbia Aparecida Costa Nobre ◽

Diego Santos Oliveira ◽

Francisco Charles dos Santos Silva ◽

André Ricardo Gomes Bezerra ◽

...

Keyword(s):

Genetic Diversity ◽

Seed Quality ◽

Soybean Seed ◽

High Standard ◽

Storage Conditions ◽

Seed Vigor ◽

Soybean Cultivars ◽

High Germination ◽

Physiological Quality ◽

Almost All

This study aimed to assess the effect of genetic diversity on physiological quality of soybean seeds stored in cold chamber and under environmental conditions. Ten cultivars were assessed in a randomized factorial design (2x10). Factor 1 corresponded to two storage conditions and factor 2 to ten soybean cultivars, with four replications. The evaluated variables were total germination (G%), first count of germination (F%), percentage of abnormal seedlings (AS%), germination speed index (GSI), water content (WC), electrical conductivity (EC), dry matter of seedlings (DMS) and length of seedlings (LS). Data underwent ANOVA, followed by Scott Knott test, as well as multivariate analysis of genetic diversity. The results showed a higher physiological quality for seeds under cold storage. Half of the cultivars (FPS Júpiter, FPS Urano, FPS Antares, FPS Netuno and CD 250) presented high germination rates and seed vigor, being thus indicated as high-standard materials for further breeding programs. Besides that, storage environment had influence on the clustering of soybean cultivars. Moreover, cultivars had genetic dissimilarity for almost all assessed traits as G%, GSI, F%, AS%, EC, DMS and LS.

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