The Texas A&M Stone Fruit Breeding and Genetics program developed peach and nectarine varieties adapted to a humid, mild winter climate.
This long-range project involved yearly cycles of evaluation and hybridization and the basic plant breeding approach of phenotypic recurrent selection. The thrust of the applied plant improvement work is breeding for consistent yield and fruit quality under mild winter conditions. Horticultural traits being introgressed into the low chill stone fruit breeding population include high sugars, low acidity, white/orange/red flesh, high firmness, flat fruit shape, and nectarine. This work has resulted in the release of 40 low and medium chill peach and nectarine varieties that have yellow and white flesh, low to high acidity, and flat to round shapes.
Internationally, the program has worked with collaborators in Brazil, Thailand, Taiwan, China, France, Spain, Morocco, South Africa, Egypt, Italy and Mexico.
The program worked toward improved breeding procedures utilizing the advances in molecular genetics to accelerate the breeding process. In collaboration with the national research effort RosBREED, molecular tools for the rapid selection for fruit size, fruit maturity, bacterial leaf spot resistance, fruit quality, and post-harvest traits are being incorporated into the breeding efforts.
The program is located within the Department of Horticultural Sciences at Texas A&M University in College Station, Texas and has collaborated with a range of private and public organizations/companies throughout the years to efficiently accomplish its breeding work.
These collaborations have been key in the breeding program with respect to germplasm acquisition/interchange, the development of the breeding populations needed for the selection process, and the locations in various ecological sites for both primary seedling selection and advanced selection evaluation trials.
Most recently, the primary seedling selection has occurred south central Texas in College Station (30º 37’ north latitude, 96° 22’ west longitude, 94 m elevation) and Floresville (29º 11’ north latitude, 98º 5’ west longitude, 510 foot elevation). Previously some seedling selection work was done in south Texas in Weslaco (26.1˚ north latitude) at the Texas AgriLife Research and Extension Center and the Texas A&M Citrus Center as well as in collaboration with private partners in Sonora, Mexico.
Second stage evaluation trials have been run at multiple sites over the life of the program. This has included important collaborations in California, Mexico, and Texas. These collaborations have been and are essential to the success of the program. In Texas, we have collaborated with commercial producers throughout the state mainly in the south central and northern low to medium chill zones.
Chilling, Temperature, and Precipitation Summary
In most Texan sites, especially as you move towards the east, there are frequent rains during bloom through June. Consequently, diseases such as bacterial leaf spot, bacterial canker, peach scab, and brown rot are common. The common insect pests are catfacing insects (plant bugs, stink bugs), thrips, and scale (San Jose and white peach). The chilling in Texas varies widely from year to year (see Chilling Accumulation article), as does the occurrence of low temperatures during bloom (Table 1) (see Frost Probability article).