Location: Vegetable Research
Project Number: 6659-21000-016-00-D
Project Type: Appropriated
Start Date: Apr 22, 2008
End Date: Sep 30, 2011
Develop pinkeye-type southernpea (cowpea) lines that exhibit yield potential equivalent to leading blackeye-type bean cultivars. Identify host-plant resistance to emerging viral diseases (e.g., Tomato spotted wilt) in southernpea genetic resources and determine the genetic control of resistance. Develop open-pollinated advanced breeding lines of sweet peppers (Capsicum annuum) and Habanero-type peppers (C. chinense) highly resistant to root-knot nematodes. Develop Habanero-type F1 hybrid pepper cultivars which are tolerant to heat stress and highly resistant to Tomato spotted wilt virus, Pepper mottle virus, and root-knot nematodes.
The southernpea pinkeye-type cultivar GreenPack-DG and the high-yielding blackeye bean cultivar California Blackeye No. 46 will be used as the parental lines to initiate a plant breeding project with the major goal of breaking the apparent yield barrier in pinkeye-type southernpeas; the two cultivars will be crossed and pedigree and single-seed-descent breeding procedures will be employed to quickly advance progeny populations three generations per year (spring field cycle, fall field cycle, and a winter greenhouse cycle). Efforts to identify sources of resistance to Tomato spotted wilt virus (TSWV) in southernpea will involve the development of an efficient and effective methodology for evaluating germplasm and then the progressive evaluation of all available sources of resistance to other cowpea viruses, a collection of named southernpea and blackeye bean cultivars, and the 720 accession core of the USDA cowpea germplasm collection. If a source of TSWV resistance is identified, the methods of classical genetics will be employed to determine the genetic control of that resistance. A backcross breeding procedure will be used to incorporate a dominant root-knot nematode resistance gene into several non-bell, open-pollinated, sweet-type peppers; a similar approach will be used to incorporate a dominant resistance gene into open-pollinated Habanero-type peppers. An effort will be initiated to develop a series of candidate F1 hybrid Habanero-type cultivars that are resistant to root-knot nematodes and the major viral diseases and tolerant to heat stress. The USDA-developed, open-pollinated, Habanero-type cultivar TigerPaw-NR will be crossed with open-pollinated Habanero-type accessions from the Texas A&M University; TigerPaw-NR is a well adapted, high yielding cultivar that is homozygous for a dominant gene conditioning resistance to root-knot nematodes and the Texas accessions are homozygous for dominant genes conditioning resistance to Tomato spotted wilt and Pepper mottle viruses, compact plant habit, and the ability to set fruit during periods of high temperatures.