Author
HANCOCK, W.G. - North Carolina State University | |
BARREIRO, F.R.C. - North Carolina State University | |
COPELAND, S.C. - North Carolina State University | |
HOLLOWELL, J.W. - North Carolina State University | |
ISLEIB, T.G. - North Carolina State University | |
STALKER, H.T. - North Carolina State University | |
Tallury, Shyamalrau - Shyam |
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 5/1/2017 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The peanut (Arachis hypogaea L.) crop in North Carolina is subject to yield and quality loss from a number of diseases including Cylindrocladium black rot (CBR) caused by Cylindrocladium parasiticum, early leaf spot (ELS) caused by Cercospora arachidicola, late leaf spot (LLS) caused by Cercosporidium personatum, Sclerotinia blight (SB) caused by Sclerotinia minor, and tomato spotted wilt virus (TSWV) caused by Tomato spotted wilt tospovirus. Although cultural and chemical management practices are available, they are costly and complete control may be difficult to achieve. Planting resistant cultivars is the preferred disease management strategy for growers, but favorable genetic variation influencing disease resistance can be limited in cultivated peanut germplasm pools. Several wild diploid species of Arachis have high levels of resistance to multiple diseases and could serve as a source of favorable alleles to improve these economically important traits. The wild diploid species A. diogoi, specifically accession GKP 10602 (PI 276235), is highly resistant to multiple diseases that impact peanut production. The objective of this research was to evaluate resistance to multiple diseases of an interspecific hybrid derived population developed from a cross between cultivated tetraploid peanut, A. hypogaea (2n=4x=40) and the diploid wild species A. diogoi (2n=2x=20). A sterile triploid F1 hybrid (2n=3x=30) resulting from the cross between a large seeded virginia-type cultivar ‘Gregory’ and the A. diogoi accession GKP 10602 was chromosome doubled to restore fertility at the hexaploid level (2n=6x=60). The hexaploid plant and resulting progeny were allowed to self-pollinate with no artificial selection for twelve generations. Spontaneous chromosome loss occurred during the selfing process and led to many segregants with A. hypogaea plant growth habit. Preliminary flow cytometry analyses confirmed that many segregants were tetraploid. Approximately 90 fertile lines were isolated from these tetraploids and this set of introgression lines was evaluated for resistance to multiple diseases using greenhouse inoculations and field evaluations. A wide range of resistance to each of the above mentioned diseases was observed in both greenhouse and field evaluations. Fourteen introgression lines are apparently highly resistant to immune to TSWV and early leafspot. Moderate levels of resistance were observed for Sclerotinia blight and CBR, with eight and nine introgression lines having greater resistance than the most resistant check for Sclerotinia blight and CBR, respectively. Eighteen introgression lines had high levels of resistance across multiple disease evaluations compared to resistant cultivars. The results are being confirmed in additional replicated field evaluations. The presence of multiple disease resistance introgression lines will aid in the long term goal of developing multiple disease resistant high yielding good quality virginia-type peanut cultivars. |