Shyam Tallury

Screening of Virginia-Type Peanut Breeding Lines for Resistance to Cylindrocladium Black Rot and Sclerotinia Blight in the Greenhouse

Abstract Cylindrocladium black rot (CBR) caused by Cylindrocladium parasiticum and Sclerotinia blight caused by Sclerotinia minor are two economically important diseases of peanut (Arachis hypogaea...

Transpiration Response to Vapor Pressure Deficit in Field Grown Peanut

Abstract Water deficit, i.e., rainfall amounts and distribution, is the most common abiotic stress that limits peanut production worldwide. Even though extensive research efforts have been made to ...

Comparison of Virginia-Type Peanut Cultivars and Interspecific Hybrid Derived Breeding Lines for Leaf Spot Resistance, Yield, and Grade

Disease resistant cultivars with good quality are needed by U.S. peanut growers to lower production costs. In the Virginia-Carolina (V-C) production area, use of resistant cultivars to reduce leaf spots would be a cost-effective and environmentally safe alternative to chemical applications. Twenty-six interspecific hybrid derived breeding lines with 5 Arachis species in their pedigrees, six resistant A. hypogaea checks and 11 susceptible cultivars were evaluated for leaf spot resistance in field tests at the Peanut Belt Research Station in Lewiston, NC from 2004 to 2006 without leaf spot fungicides. Defoliation was rated on a 1–9 proportional scale with 1 = no defoliation (resistant) and a 9 = complete defoliation (susceptible). The mean defoliation score of the cultivars was 6.8±0.1 (range = 6.4 to 7.4), compared to 5.3±0.1 (range = 4.4 to 6.3) for the interspecific hybrid derived breeding lines. Some of the interspecific hybrid derived breeding lines showed levels of leaf spot resistance similar to the resistant A. hypogaea checks (mean = 4.3±0.2), suggesting that these breeding lines contain genes conditioning resistance to the leaf spots. The combined mean yield of the cultivars was 2709±103 kg/ha (range = 2296 kg/ha to 3070 kg/ha), whereas that of the interspecific hybrid derived breeding lines was 3169±119 kg/ha (range = 2467 kg/ha to 3767 kg/ha). Evaluation of selected grade characteristics showed that several interspecific hybrid derived breeding lines have grade similar to those of the commercial cultivars. Sixteen of the 26 interspecific hybrid derived breeding lines with five different diploid species in their pedigrees and NC 7, the commercial flavor standard for the V-C area, were also evaluated for sensory quality. No significant variation among test entries was found for the roasted peanut, sweet, or bitter sensory attributes. This suggests that high levels of leaf spot resistance can be combined with superior yield, grade and other quality factors and that some of these lines may become useful for commercial production in the V-C area.

Heat Stress Related Physiological and Metabolic Traits in Peanut Seedlings

ABSTRACT To maintain high yields under an increasingly hotter climate, high temperature resilient peanut cultivars would have to be developed. Therefore, the mechanisms of plant response to heat need to be understood. The objective of this study was to explore the physiological and metabolic mechanisms developed by virginia-type peanut at early growth stages in response to high temperature stress. Peanut seedlings were exposed to 40/35 C (heat) and 30/25 C (optimum temperature) in a growth chamber. Membrane injury (MI), the Fv/Fm ratio, and several metabolites were evaluated in eight genotypes at four time-points (day 1, 2, 4, and 7) after the heat stress treatment initiation. Even though we were able to highlight some metabolites, e.g., hydroxyproline, galactinol, and unsaturated fatty acid, explaining specific differential physiological (MI) responses in peanut seedlings, overall our data suggested general stress responses rather than adaptive mechanisms to heat. Rather than individual metabolites, a co...

Flavor Profiles of Wild Species-Derived Peanut Breeding Lines

Abstract Several diploid wild species of the genus Arachis L. have been used as sources of resistance to common diseases of cultivated peanut (Arachis hypogaea L.). Because flavor is among the most important quality attributes for commercial acceptance of roasted peanuts, sensory attributes of interspecific hybrid derived breeding lines were evaluated to determine if transfer of disease resistance from wild species is associated with concomitant changes in flavor. Sixteen interspecific hybrid derivatives with five diploid species in their ancestries and the commercial flavor standard, NC 7 were evaluated for sensory quality. Significant variation among entries was found for the roasted peanut, sweet, and bitter sensory attributes, but not for the overall contrast between NC 7 and the wild species-derived breeding lines. The variation was either between two groups of wild species-derived breeding lines or within one or both groups. Introduction of disease and pest resistance traits from Arachis species did...