MSI01P3586 | |
Ramdoyal, K. Sullivan, S. Badaloo, G. H. Dhayan, S. Saumtally, S. Domaingue, R. | |
Inheritance of resistance to yellow spot in segregating populations of sugarcane | |
periodical article | |
2001 | |
Proc. int. Soc. Sug. Cane Technol. | |
24(2): 422-429 | |
En | |
En Fr Es | |
The inheritance of resistance to yellow spot in eleven families (parent varieties and progeny) was studied over three disease evaluation dates over two years. The study showed that the control and parent varieties could be consistently classified in the disease reaction classes assigned from previous field trials. The absolute infection level of a control or parent clone and families fluctuated owing to seasonal variation in infection pressure. There was a clear tendency for the mean infection level of the progeny to increase as the combined susceptibility of the parents increased. Narrow-sense heritability derived from the partitioning of variances between and within families varied from 0.68-0.71 when infection was relatively low, increased to 0.83 under severe infection pressure and was very high, 0.98, when it was derived from data pooled over all evaluation dates. Frequency distributions of infection pooled over evaluation dates showed a fairly wide distribution of progenies with transgressive segregants occurring in the lower and higher susceptibility classes in all categories of crosses. The distribution was skewed towards the lower infection classes for crosses among resistant and slightly susceptible parents, whereas it tended towards a binomial distribution in crosses which involved a susceptible or highly susceptible parent. The mode of segregation indicated an oligogenic system with often a quantitative expression for the trait. Parent clones and families differed widely with respect to infection level but parent x date or year and family x date or year interactions were not important within the same year of evaluation or between years, which indicated very high broad-sense heritability of 0.89-0.95. The significance of these findings in designing a sound breeding strategy for yellow spot resistance is discussed. | |
Sugarcane diseases disease resistance Yellow spot breeding heritability Mycovellosiella koepkei resistance | |
Mauritius | |
Cane breeding and genetic improvement | |
Disease resistance | |
2001-09-20 | |
En | |
Path PB |