QTL mapping of sugar cane resistance to brown spot (Cercospora longipes)

Code (CO)	MSI06P4221
Author (AU)	Aljanabi, S. M. Parmessur, Y. Kross, H. Dhayan, S. Saumtally, S. Dookun-Saumtally, A.
Title - English (ET)	QTL mapping of sugar cane resistance to brown spot (Cercospora longipes)
Thesis-Parent title (TH)	Abstracts, 5th ISSCT Molecular Biology Workshop, 3-7 April 2006, Réduit, Mauritius
Document Type(DT)	Conference paper
Date of publication (DP)	2006
Source (SO)	p. 1.2
Notes (NO)	Abstract only
Language of text (LT)	En
Language of summaries (LS)	En
Abstract (AB)	Brown spot caused by the fungus Cercospora longipes, Butler, is widely spread in many sugar-producing countries. However, no molecular studies are available to date to identify quantitative trait loci (QTL) for resistance to this disease. A genetic linkage map was generated in a segregating population of 227 progeny derived from a cross between resistant (M 143/75) by susceptible (R 570) varieties to facilitate the identification of such QTLs. The amplified fragment length polymorphism (AFLP) and microsatellites (SSR) markers were used to generate 722 polymorphisms in the segregating population, scored as present in M 134/75 alone and absent in R 570. Thirty-six AFLP primer combinations screened against the 227 progeny generated 556 polymorphisms and 65 SSR primers screened added 166 additional polymorphic alleles. The 722 polymorphisms were used to calculate SDMs, utilized to construct a genetic linkage map of cultivar M 134/75. Out of the 722 polymorphic markers, 607 were SDMs segregating 1:1. Linkage analysis assigned 524 SDMs (404 AFLP and 120 SSRs) to 98 LGs containing at least two linked markers with a total of 83 markers remained unlinked. A framework map of variety M 134/75 consisted of 524 single does markers (segregating 1:1 as present:absent) was constructed. Twelve genomic regions were associated with the resistance to brown spot. Nine of the putative QTLs were found on different linkage groups and three were unlinked. Out of the 9-mapped putative QTL, 5 were identified by AFLP markers, while the remaining four by SSR markers. The percentage of phenotypic variation explained by the linear regression on individual markers ranged from 4.2-11.1 per cent. This study provides a framework for future investigation of brown spot disease resistance in sugar cane.
Descriptors - English (DE)	sugarcane diseases disease resistance brown spot QTL Cercospora longipes
Descriptors - Geographic (DG)	Mauritius
Sort Key 1(K1)	Sugarcane: Diseases and disease management
Sort Key 2 (K2)	Brown spot
Date record entered (DA)	2006-12-28
Language of analysis (LA)	En
Location (LO)	Biotech
MSIRI Staff (MS)	Biotech path