ARS | Publication request: Peanut seed vigor elavuation using a thermal gradient

Submitted to: International Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 10, 2011
Publication Date: August 1, 2011
Citation: Grey, T.L., Beasley, J.P., Webster, T.M., Chen, C.Y., Bridges, D.C. 2011. Peanut seed vigor elavuation using a thermal gradient. International Journal of Agronomy. DOI: 10/1155/2011/202341.

Interpretive Summary: Prior to the 1990’s, peanut in Georgia was planted in April. However, the incidence of tomato spotted wilt Tospovirus (TSWV) increased rapidly across the peanut belt. Research demonstrated that shifting peanut planting to mid- to late-May minimized the impact of TSWV. Breeders have continued to develop new peanut cultivars with TWSV resistance with a goal to revert to April planting to increase growers’ overall planting and harvesting efficiency. Studies were conducted to evaluate seed germination response of multiple peanut cultivars to a temperature gradient ranging from 14 to 35 C. Two indices, maximum germination and GDD value at 80% of germination rate, were used to evaluate seed germination by variety. Cultivars with the strongest seed vigor and maximum seed germination were ‘AT 3081R’, ‘AP-3’, ‘GA06G’, and ‘Carver’. Other cultivars (‘C99R’, ‘Georgia-01R’, ‘Georgia-02C’, and ‘Georgia-03L’) had inconsistent seed performance, failing to achieve 80% germination in at least two of the years. These data assisted in determining variation for peanut seed among various cultivars when grown by seed producers under known environmental conditions. Future research should emphasize comparisons using this technique for peanut breeder seed grown under similar environments to determine if genotypic variations for seed vigor can be determined among cultivars.

Technical Abstract: Experiments were conducted from 2007 to 2009 to evaluate the seed germination response of multiple peanut cultivars using a continuous temperature gradient ranging from 14 to 35 C (1.0 C increments). Growing degree day (GDD) accumulation for each temperature increment was measured. Two indices, maximum germination and GDD value at 80% of germination rate (Germ80), were used to elucidate seed germination performance by variety. Based on the two indices, the most consistent cultivars were ‘AT 3081R’, ‘AP-3’, ‘GA06G’, and ‘Carver’ with the strongest seed vigor (Germ80 26 to 47) and a maximum germination rate (80 to 94%). The other cultivars (‘C99R’, ‘Georgia-01R’, ‘Georgia-02C’, and ‘Georgia-03L’) had inconsistent seed performance, failing to achieve 80% germination in at least two of the years. These data indicated that a thermogradient apparatus could be successfully used to evaluate peanut cultivars for seed vigor, with analysis using a sigmoidal curve to provide information on germination characteristics. Meaningful differences in germination were detectable by 72 hrs over a temperature range of 15 to 30 C. These data assisted in determining variation for peanut seed among various cultivars when grown by seed producers under known environmental conditions. Future research should emphasize comparisons using this technique for peanut breeder seed grown under similar environments to determine if genotypic variations for seed vigor can be determined among cultivars.