The U. S. Department of Agriculture released the small-seeded, cream-type southernpea cultivar Green Pixie on 4 Mar. 1999. The new cultivar is homozygous for the gc gene conditioning the green cotyledon trait. `Green Pixie' seeds can be harvested at the dry stage of maturity without loss of their fresh green color. `Green Pixie' originated as a bulk of an F9 (`White Acre' × `Bettergreen') population grown in 1994. `Green Pixie' has a high, bushy plant habit similar to `White Acre'. It produces dry pods at Charleston, S.C., in ≈76 days, 5 days later that `Bettergreen' and 5 days earlier than `White Acre'. The rhomboid-kidney shape of fresh `Green Pixie' seeds is quite similar to the shape of fresh `White Acre' seeds, but very different from the ovate to reniform shape of fresh `Bettergreen' seeds. `Green Pixie' seeds are quite similar in size to `White Acre' seeds, but much smaller than `Bettergreen' seeds (weight per 100 dry seeds: `Green Pixie', 8.0 g; `White Acre', 7.9 g; and `Bettergreen', 10.2 g). The results of replicated field trials indicate that the yield potential of `Green Pixie' is equal to that of `Bettergreen' and `White Acre'. `Green Pixie' is the first cream-type, green-cotyledon cultivar to be developed that yields seeds that are similar in size and shape to `White Acre' seeds. It is recommended for trial as a replacement for `White Acre' when grown to produce raw product for a frozen pack.
A breeding program was initiated in 1990 to develop a pinkeye-type southernpea [Vigna unguiculata (L.) Walp.] cultivar homozygous for the gc gene conditioning green cotyledons. The pinkeye is the leading cultivar class of southernpea grown in the U.S., and there is considerable interest in converting pinkeye germplasm to green cotyledon phenotypes because a cultivar homozygous for the gc gene can be harvested at the near-dry seed stage of maturity without loss of the seed's fresh green color. Seeds containing embryos homozygous for the gt gene are easily identified, and this ability to select in the seed stage greatly facilitated breeding efforts. A total of 25 advanced breeding lines (F9 and F10) were evaluated in preliminary field tests in 1995, and the experimental line US-858 was selected for seed multiplication, field testing, and raw product evaluation in 1996. The results of 1996 replicated yield trials conducted in South Carolina and seed multiplication plantings grown in El Salvador, Georgia, and Florida indicate that the maturity, seed, and yield characteristics of US-858 are comparable to those of the leading pinkeye-type cultivars. Raw product evaluations were conducted at a commercial freezing facility in Georgia, and the results indicate that US-858 produces an excellent processed product. The results of field inoculation tests conducted in Georgia indicate that US-858 is resistant to blackeye cowpea mosaic virus, the major pathogen of southernpea in the U.S.
The development of southernpea (Vigna unguiculata) cultivars with a persistent green seed color has been the subject of much interest for more than two decades because seeds of such cultivars can potentially be harvested at the near-dry seed stage of maturity without loss of their fresh green color. The success of the cream-type cultivar Bettergreen, which is homozygous for the gc gene conditioning green cotyledons, demonstrated that the development of cultivars with persistent green seed color is feasible. In 1990, an effort was initiated to develop a pinkeye-type southern pea cultivar homozygous for the gc gene. The pinkeye is the major cultivar class of southernpea utilized for processing in the United States. Seeds containing embryos homozygous for the gc gene are easily identified, and this ability to select in the seed stage greatly facilitated the rapid development of advanced breeding lines. More than two dozen advanced generation pinkeye lines with green cotyledons were ready for preliminary field testing in 1995, and seven were selected for detailed evaluation in 1996. Results of the 1996 tests indicate that the gc gene has been successfully incorporated into elite pinkeye germplasm.
R. L. Fery and P. D. Dukes
The Agricultural Research Service of the United States Department of Agriculture announced the release of Carolina Crowder southernpea on 12 October 1990. The new cultivar is well adapted for production throughout the southern U.S., where it can be expected to produce excellent yields of high quality, crowder-type peas. Carolina Crowder is resistant to the cowpea curculio, the major insect pest of the southernpea in southeastern production areas; blackeye cowpea mosaic virus, an important virus pathogen of southernpea in the United States; and root-knot, a severe root disease incited by several species of the root-knot nematode. Canned samples of fresh Carolina Crowder peas scored well in three years of quality evaluation tests. Pod color is a brilliant red at early green-shell maturity and a brilliant red heavily shaded with cranberry colored pigment at optimum green-shell maturity. The attractive pod color should make Carolina Crowder an excellent candidate for fresh market use. Carolina Crowder plants have a greater tendency to produce a second crop than plants of most southernpea cultivars.
R. L. Fery and J. M. Schalk
A greenhouse study was conducted to confirm the availability of resistance in pepper (Capsicum annuum L.) to western flower thrips [Frankliniella occidentalis Pergande)]. Host plant resistance ratings confirmed earlier observations that there is a considerable amount of variability within pepper germplasm for reaction to F. doccidentalis. Plants of `California Wonder', `Keystone Resistant Giant', `Mississippi Nemaheart', `Sweet Banana' and `Yolo Wonder L' were resistant to the insect and exhibited only mild injury. Plants of `Bohemian Chili', `Carolina Cayenne', and `Santaka', however, exhibited the symptoms of severe thrips injury, i.e., poorly expanded, deformed and distorted leaves, greatly shortened internodes, and severe chlorosis. The resistance in pepper to F. occidentalis appears to be due to tolerance mechanisms, not nonpreference or antibiosis mechanisms. The levels of resistance identified in this study are sufficiently high to justify the initiation of breeding efforts to transfer F. doccidentalis resistance into susceptible pepper cultivars.
P. D. Dukes and R. L. Fery
A useful and novel cayenne pepper (Capsicum annuum L.) breeding line has been released by ARS, USDA, U. S. Vegetable Laboratory. This new Line, designated and tested as PA-136, has a high level of tolerance to massive infection by root-knot neamtodes (Meloidogyne spp.) to which it is susceptible. PA-136 has proven to be useful as a host for the abundant production of eggs for several Meloidogyne species, including all 4 races of M. incognita. Availability of large quantities of egg inoculum of these obligate parasites is a pre-requisite for successful and efficient breeding for root-knot resistance. PA-136 plants are vigorous, strong and uniformly branched, and reach a height of about 60 cm. The line has many good horticultural traits, including high yield, deep red fruit color, and high pungency. PA-136 is stable for all traits needed for the production of large numbers of viable eggs. Eggs are easily collected when needed from fresh roots using the Hussey-Barker extraction procedure (Plant Dis. Reptr. 57:1025-1028. 1973).
R. L. Fery and P. D. Dukes
The Agricultural Research Service of the United States Department of Agriculture announced the release of `Bettergro Blackeye' southernpea on 24 July 1991. The new cultivar is well adapted for production throughout the southern United States where it can be expected to produce excellent yields of high quality, blackeye-type peas. `Bettergro Blackeye' outyielded the `Pinkeye Purple Hull-BVR' check in the 1986, 1987, 1988, and 1989 Regional Southernpea Cooperative Trials by 34.8, 14.3, 12.6, and 20.9%, respectively. Canned samples of fresh `Bettergro Blackeye' peas scored well in three years of quality evaluation tests. The new cultivar is resistant to the cowpea curculio, the major insect pest of the southernpea in southeastern production areas, and root knot, a severe root disease incited by several species of the root-knot nematode. `Bettergro Blackeye' plants have a greater tendency to produce a second crop than plants of most southernpea cultivars.
R. L. Fery and P. D. Dukes
The results of recently completed genetic studies indicate that the green cotyledon trait exhibited by the southernpea [Vigna unguiculata (L.) Walp.] cultivar Bettergreen is conditioned by a single recessive gene. This gene, designated green cotyledon and symbolized gc, is neither allelic to nor linked with the gt gene that conditions the green testa trait exhibited by the cultivar Freezegreen. The color of seeds harvested from plants homozygous for both the gc and gt genes is superior and more uniform than the color of seeds harvested from either Better-green or Freezegreen plants. This observation suggests that efforts should be initiated to study the feasibility of using both the gc and gt genes to develop cultivars that produce seed with an enhanced, persistent green color. The selection methodology for both seed traits is rapid and reliable. The green cotyledon trait can be selected in the seed stage.
R. L. Fery and P. D. Dukes
Bettersnap southernpea (Vigna unguiculata) was developed as a replacement for the popular cultivar Snapea. The new cultivar is well adapted for production throughout the southern United States where it can be expected to produce excellent yields of edible pods or snaps. Bettersnap is resistant to root knot, a severe root disease incited by several species of the root-knot nematode (Meloidogyne spp.), and blackeye cowpea mosaic virus, the major pathogen of southernpea in the United States. Observations of natural epiphytotics indicate that the cultivar is also resistant to scab (Cladosporium vignae) and cercospora leaf spot (Cercospora cruenta). The new cultivar has the same maturity and high yield potential as Snapea. Bettersnap is recommended for use as a home garden cultivar for spring, mid-season, and fall plantings. It is particularly recommended for trial as a commercial processing cultivar for the production of the immature green pods used for the ``snap” component of the popular mixed packs of fresh peas and green snaps.
R.L. Fery and J.A. Thies
The peanut root-knot nematode (Meloidogyne arenaria race 1) is potentially a major pest of pepper cultivars belonging to the species Capsicum chinense. Greenhouse tests were conducted to: 1) compare the level of resistance to the peanut root-knot nematode exhibited by the recently released C. chinense germplasm line PA-353 to that exhibited by the C. annuum cv. Carolina Cayenne; 2) to determine the inheritance of the resistance in the C. chinense germplasm line PA-353; and 3) to determine the genetic relationship between the resistance exhibited by the C. chinense germplasm line PA-353 and that exhibited by the C. annuum cv. Carolina Cayenne. The level of resistance exhibited by the C. chinense germplasm line PA-353 was equal to the high level of resistance of the C. annuum cv. Carolina Cayenne. Evaluation of parental, F1, F2, and backcross populations of the cross between the resistant C. chinense germplasm line PA-353 and the susceptible C. chinense accession PA-350 indicated that the resistance in C. chinense is conditioned by a single dominant gene. The F2 population of the interspecific cross between the resistant C. chinense germplasm line PA-353 and the resistant C. annuum cv. Carolina Cayenne did not segregate for resistance, indicating that the dominant resistance gene in C. chinense is likely allelic to or closely linked to a gene conditioning resistance in C. annuum. The availability of a simply inherited source of outstanding resistance makes breeding for peanut root-knot nematode resistance a viable objective in C. chinense breeding programs.