|SOUTER, JODI - University Of Saskatoon|
|GURUSAMY, VALARMATHI - University Of Saskatoon|
|Porch, Timothy - Tim|
|BETT, KIRSTIN - University Of Saskatoon|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2017
Publication Date: 5/5/2017
Citation: Souter, J.R., Gurusamy, V., Porch, T.G., Bett, K.E. 2017. Successful introgression of abiotic stress tolerance from wild tepary bean to common bean. Crop Science. 57:1-12.
Interpretive Summary: Common bean lacks drought stress and sub-zero temperature stress tolerance which is detrimental to production and will become more significant due to climate change and the redistribution of production areas. Efforts to increase tolerance in common bean have not been sufficient. Introgressing genes from abiotic stress tolerance relative, tepary bean, into common bean is a promising method for increasing tolerance. In this study, a BC2F6 interspecific introgression population, along with common bean and tepary bean checks, was analyzed for tolerance to a terminal water limitation stress and a seedling sub-zero temperature stress. The tepary beans were more tolerant than the rest of the population to these two stresses. Introgression lines varied in response, however several introgression lines tolerated the stresses to a greater extent than the common bean parent. This study both determined tepary beans suitable for future crosses with common beans and presented that tepary bean can be successfully introgressed to common bean to increase abiotic stress tolerance.
Technical Abstract: Common bean (Phaseolus vulgaris L.) production is severely limited due to abiotic stresses, including drought and sub-zero temperatures. Tepary bean (Phaseolus acutifolius Gray), a relative of common bean, has demonstrated tolerance to these stresses. Preliminary studies screening tepary accessions for cold tolerance demonstrated that W6 15578 is a potential donor of cold tolerance so an interspecific backcross population derived from a cross between it and common bean (NY5-161) was developed. Field studies were conducted in Saskatoon to identify lines able to withstand sub-zero temperatures better than the common bean parent at the seedling stage. W6 15578 previously demonstrated tolerance to drought stress, so interspecific introgression lines were tested for response to terminal drought under field conditions in Puerto Rico. Days to flowering and yield measurements along with sub-zero temperature and drought stress tolerance data are presented. Even though the interspecific introgression lines were backcrossed twice to common bean to improve the fertility, and which also increased the proportion of common bean genome, several introgression lines performed better than the common bean parent under both stress conditions. Future breeding objectives include backcrossing to tepary to try to recover additional abiotic stress tolerance genes, as well as using selected introgression lines as breeding material to develop varieties with increased sub-zero temperature stress and drought stress tolerance. The interspecific introgression of portions of the tepary bean genome into common bean is a promising method for increasing abiotic stress tolerance in common bean.