Assessment of the reaction of progeny to rust (Puccinia melanocephala H. and P. Syd.) in resistance inheritance studies
Code (CO)MSI99P2299
Author (AU)Saumtally, S.
Sullivan, S.
Moutia, Y.
Autrey, L. J. C.
Title - English (ET)Assessment of the reaction of progeny to rust (Puccinia melanocephala H. and P. Syd.) in resistance inheritance studies
Thesis-Parent title (TH)BSES - Program and Abstracts, 4th ISSCT Pathology Workshop, Brisbane, Australia, 4th-9th April 1994
Document Type(DT)Book chapter
Date of publication (DP)1994
Source (SO)p. 36
Publisher (PB)Brisbane, BSES
Notes (NO)Abstract only
Language of text (LT)En
Abstract (AB)Rust of sugarcane caused by Puccinia melanocephala is an important disease in Mauritius, particularly in the superhumid zone. In order to develop varieties with resistance to rust for specific environments, it is necessary to obtain relevant information on the inheritance mechanism of the disease. With this objective, seedlings from seven biparental crosses (that included the following type of crosses: RxR, SSxR, SxR, SxHS and RxHS) as well as a selfed resistant variety, were transferred to the field in the centre of the island where inoculum pressure was high. Each family was split into two groups and planted along with the parents and control varieties. The seedlings and the standards were bordered on each side by contaminating rows of the highly susceptible variety M1030/71. The number of seedlings per family varied from 45 to 108. Rust infection in the experiment was appreciably high and disease assessment was performed 3 months after establishment of the t rial on a scale of 0 (immune) to 3 (highly susceptible). A good correlation was found between the known reaction of the parents and the observed in that experiment. A high frequency of resistant progeny was observed in RxR (60 to 87 per cent), RxHS (80 per cent) and SSxR (67 per cent) crosses, while in the SxHS cross only 20 per cent were resistant. A proportionally higher number of susceptible to resistant progeny (3:2) was found in the SxR cross. Selfing of the resistant variety R570 gave a ratio of 3:1 of resistant to susceptible progeny. Infection was also measured using a video image analyser. The mean percentage infection on all leaves, using a sample of 6-10 seedlings representing each category on the assessment scale, was found to correspond to the following percentage infection:- 1:(less than 5 percent; 1-2: 4.5-17.3 per cent; 2: 7.2-34.3 per cent; 2-3: 10.2-45.3 per cent; and 3: 24.2-47.6 per cent. Due to the overlapping percentage of infection in visual estimation, this equipment was found to be a useful tool in studies on quantivative genetics of rust. A genetic analysis of the results will be reported elsewhere.
Descriptors - English (DE)SUGARCANE
PUCCINIA MELANOCEPHALA
DISEASE RESISTANCE
RUST
DIAGNOSTIC TECHNIQUES
DISEASES
DISEASE CONTROL
Descriptors - Geographic (DG)MAURITIUS
Sort Key 1(K1)Sugarcane: Diseases and disease management
Date record entered (DA)1996-08-08
Language of analysis (LA)En
Location (LO)PATH
MSIRI Staff (MS)PATH