The dynamic challenges of peanut (Arachis hypogaea L.) farming demand a quick response from breeders to develop new cultivars, a process that can be aided by the application of molecular markers. With the goal to pyramid nematode resistance and the trait for high oleic:linoleic acid (high O:L) ratio in seeds, nematode-resistant cultivar Tifguard was used as the recurrent female parent and high O:L cultivars Georgia-02C and Florida-07 were used as donor parents for the high O:L trait. 'Tifguard High O/L' was generated through three rounds of accelerated backcrossing using BC n F 1 progenies selected with molecular markers for these two traits as the pollen donors. Selfed BC 3 F 2 plants yielded marker-homozygous individuals identifi ed as Tifguard High O/L, compressing the hybridization and selection phases of the cultivar development process to less than 3 yr. The accuracy of marker-assisted selection (MAS) was confi rmed by phenotyping a subset of F 2:3 populations from both parental combinations. Once additional molecular markers linked with traits of interest are designed to be compatible with high-throughput screening platforms, MAS will be more widely integrated into peanut breeding programs.

‘Florida‐07’ (Reg. No. CV‐104, PI 652938) peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) cultivar was developed by the University of Florida, Florida Agricultural Experiment Station, North Florida Research and Education Center near Marianna, FL. It was approved for release in 2006. Florida‐07 has larger‐than‐average runner market–type seeds and pods. The growth habit of Florida‐07 is prostrate, typical of runner‐type peanut cultivars. Under irrigation in Florida, it matures about 140 d after planting, which places it in the category of medium‐late relative maturity. Release of Florida‐07 was made on the basis of its excellent pod yield potential, competitive kernel grade (percentage total sound mature kernels), high‐oleic fatty acid oil chemistry, and resistance to spotted wilt (caused by Tomato spotted wilt tospovirus) and white mold (Sclerotium rolfsii Sacc.).

One objective of peanut breeders is to develop cultivars with elevated oleic acid content (.740 g kg 21 ). Testing single seeds for oleic acid content is possible using gas chromatography (GC), but it is time-consuming and requires cutting a portion of the seed which could reduce germination. Using single, intact peanut seeds, we developed a near-infrared reflectance spectroscopy (NIR) calibration equation relating oleic acid measured with GC to oleic acid predicted by NIR. The slope of the regression line of oleic acid measured with GC on oleic acid predicted by NIR was 1.01 g kg 21 (P . t , .0001) and the intercept was not different from zero. An independent set of 95 peanut seeds was used to validate the NIR calibration. The slope of the regression line was 1.01 g kg 21 (P . t , .0001) and the intercept was not different from zero. By selecting seeds with at least 700 g kg 21 NIR predicted oleic acid content, only four of the 43 seeds (validation set) with elevated oleic acid content were misclassified by NIR, and none with normal oleic acid content were misidentified. Results were similar for linoleic acid content. This research shows that NIR prediction of oleic acid and linoleic acid using intact peanut seeds is accurate and rapid and should be especially useful for early generation screening.

Peanut composition is influenced by several groups of factors: environmental, genetic, and their interaction. This study evaluated the relative contributions of these factors using data from the USDA-ARS quality testing program using samples from the multi-state Uniform Peanut Performance Tests (UPPT). Data were subjected to restricted maximum likelihood estimation of variance components reflecting the main effects of year, production region, location within region, genotype (cultivar or breeding line), and kernel grade (''seed size'') within genotype, and the interactions among these main effects. Genetic variation in oil content was low (9% of total variation); however, fatty acid composition of the oil was highly influenced by genotype (34-77%) with the exception of lignoceric acid (1%). Genetic influence on tocopherols was generally less than that of fatty acids. Environmental variation of tocopherols was greater than the variation attributable to genotype-by-environment interaction. The lowest genetic variation was observed in sugar content; however, environmental variation was high (68%). The magnitude of genetic influence on oil content and fatty acid concentrations suggests that these traits are amenable to improvement through breeding.

Tomato spotted wilt, caused by Tomato spotted wilt tospovirus (TSWV) is a major problem in peanut (Arachis hypogaea L.) producing areas of the southeastern U.S. The integrated program used to manage spotted wilt relies heavily on cultivars with field resistance to TSWV, and finding new sources and greater levels of resistance to TSWV is highly desirable. Field tests were conducted in 2003 and 2004 in Marianna, FL and Tifton, GA to compare three peanut breeding lines, F NC94022-1-2-1-1-b3-B, C 11-2-39, and C 11-186 to that of standard moderately resistant cultivar Georgia Green for field response to TSWV. F NC94022-1-2-1-1-b3-B was of particular interest because it was developed from a cross between lines of A. hypogaea subsp. hypogaea var. hirsuta Kö hler and A. hypogaea subsp. hypogaea var. hypogaea. In all tests, final spotted wilt ratings for breeding lines F NC94022-1-2-1-1-b3-B, C 11-2-39, and C 11-186 were lower and pod yields were higher than for Georgia Green. In three tests, final spotted wilt intensity ratings did not differ among F NC94022-1-2-1-1-b3-B, C 11-2-39, and C 11-186. At Marianna in 2004, spotted wilt intensity ratings were lower and pod yields were higher in F NC94022-1-2-1-1-b3-B than in any other entry. The high level of field resistance to TSWV in F NC94022-1-2-1-1-b3-B is presumably derived from its hirsuta type parent, PI 576638.