The USDA has released a new, pinkeye-type southernpea cultivar that is homozygous for the gc gene conditioning the green cotyledon trait. The new cultivar, `Charleston Greenpack', can be harvested at the near-dry stage of pod maturity without loss of the pea's fresh green color. `Charleston Greenpack' originated as a bulk of an F8 [`Kiawah' × (`Kiawah' × `Bettergreen')] population grown in 1994. Except for the green seed color, a tendency for a slightly greener foliage, and a slightly smaller pea size, the phenotype of `Charleston Greenpack' is quite similar to those of `Coronet' and `Pinkeye Purple Hull-BVR'. The results of replicated field tests indicate that `Charleston Greenpack' yields are comparable to those of `Coronet' and `Pinkeye Purple Hull-BVR'. Results of raw product evaluations conducted at a commercial freezing facility indicate that `Charleston Greenpack' produces an excellent processed product. `Charleston Greenpack' has excellent field resistance to blackeye cowpea mosaic virus, the major pathogen of southernpea in the United States.
Richard L. Fery
The use of multidisciplinary teams has been the key to making progress in the development of insect resistant southernpea [Vigna unguiculata (L.) Walp.] and tomato (Lycopersicon esculentum Mill.) cultivars; both the plant breeder and the entomologist have primary program responsibilities. The basic approach encompasses three separate but interrelated phases: 1) evaluation of germplasm collections to locate needed sources of resistances, 2) genetic studies to determine the inheritance of resistances, and 3) breeding programs to transfer resistance genes into adapted germplasm. The basic approach must usually be supplemented by concurrent research to, determine the nature and value of resistances and to develop evaluation procedures, selection criteria, and plant breeding methodologies. Selected examples from research projects on southernpea (resistances to cowpea curculio, southern green stinkbug, leaf footed bug, leaf miners, and thrips) and tomato (resistances to tomato fruitworm, tobacco hornworm, and Colorado potato beetle) will be used to illustrate approaches and methodologies.
Richard L. Fery
The USDA–ARS has released a new pinkeye-type southernpea cultivar named GreenPack-DG. GreenPack-DG is the first pinkeye-type southernpea to be released that has a persistent green seed phenotype conditioned by both the green cotyledon gene (gc) and the green testa (gt) gene. The new cultivar was developed from a cross between Charleston Greenpack (green cotyledon phenotype) and the breeding line USVL 97-296 (green testa phenotype). Except for longer pods, GreenPack-DG is similar in appearance and maturity to Charleston Greenpack. Dry GreenPack-DG seeds have a richer and more-uniform green seed color than dry seeds of Charleston Greenpack. GreenPack-DG seeds are much less susceptible to color loss due to blanching when harvest is delayed than are seeds of green-cotyledon cultivars such as Charleston Greenpack. Color loss is a critical problem in production systems where preharvest desiccants are used to facilitate mechanical harvesting operations. The 7-day delay between application of the desiccant and initiation of harvesting operations can result in serious color degradation. Results of 3 years of replicated field tests at Charleston, S.C., indicate that GreenPack-DG yields are comparable to Charleston Greenpack yields. The new cultivar has excellent field resistance to blackeye cowpea mosaic virus and does not produce hard seeds. GreenPack-DG is recommended for trial by the frozen food industry as a replacement for Charleston Greenpack. Protection for GreenPack-DG is being sought under the Plant Variety Protection Act.
Richard L. Fery
The USDA has developed four pinkeye-type southernpea candidate cultivars (Experimental designations: US-1090, US-1092, US-1094, and US-1096) that have a persistent green seed phenotype conditioned by both the green cotyledon gene (gc) and the green testa (gt) gene. Each of the candidate cultivars produces dry seeds that have a richer and more uniform green color than seeds of either green cotyledon or green testa phenotype cultivars. Seeds of these candidate cultivars are much less susceptible to color loss due to blanching when harvest is delayed than are seeds of green cotyledon phenotype cultivars. Color loss is a critical problem in production systems where pre-harvest chemical desiccants are used to facilitate mechanical harvesting operations. The 7-day delay between application of the desiccant and initiation of harvesting operations can result in serious color degradation. The results of four 6-replicate field trials indicate that the yield potential of each of the four candidate cultivars is equal to that of the green cotyledon pinkeye-type cultivar Charleston Greenpack. Additionally, each of the candidate cultivars is resistant to blackeye cowpea mosaic virus and do not produce hard seeds that are troublesome to frozen food processors. The seed shape, seed size, and seed eye pattern traits of the candidate cultivars are similar to those of Charleston Greenpack.
Richard L. Fery
A breeding program was initiated in 1990 to develop cream-, blackeye-, and pinkeye-type southernpea [Vigna unguiculata (L.)] cultivars homozygous for the gc gene conditioning green cotyledons. The green cotyledon trait allows harvest at the near-dry seed stage of maturity without loss of the seed's fresh green color. The ability to select for the gc gene in the embryo stage greatly facilitated its use in breeding programs, and the development of advanced breeding lines has proceeded at an accelerated rate. Sixteen F9 and 15 F10 breedinglines homozygous at the gc locus were available for preliminary field testing in 1995. The results of this field testing indicate that the efforts to incorporate the gc gene into elite horticultural germplasm have been successful. More importantly, the results of tests conducted with seed harvested at the dry stage of maturity indicate that several of the lines should produce an excellent processed product.