Thousands of QTL and genes conferring
traits of agronomic importance have been identified in major crops, and these can be used to accelerate MAS. At present, QTL detection and functional analysis are separate from MAS. Many molecular markers for targeting NVP-BKM120 manufacturer genes/loci are not useful during the selection process because of low polymorphism across different genetic backgrounds and incomplete association with target traits. In this study, we attempted to select promising breeding lines with FHB resistance and good agronomic traits by combining QTL analysis and MAS. In a recombinant inbred line (RIL) population derived from cultivars Yanzhan 1 (YZ1) and Neixiang 188 (NX188) FHB resistance and other important agronomic traits were simultaneously selected using molecular markers, and several elite lines were produced. One hundred and ninety nine F7:8 RILs were developed by single-seed descent from the cross YZ1 × NX188. YZ1 is an early maturing cultivar released in Henan Province of China, in 2000; NX188, a high yielding cultivar with wide adaptation and released in 2000, was the fourth most widely planted cultivar in China (470,000 ha) in 2004. The RILs and their parents were planted in Beijing and in Luoyang, Henan province, in the 2003–2004 and 2004–2005 wheat seasons. All lines were phenotyped as single relicates in four environments.
selleckchem Thirty seeds of each line were sown in a two-row plot of 2 m in length. Plant height (PH) was measured in the field at maturity. Spike length (SL), spikelet number per spike (SPI), spike compactness (SC, SC = SPI/SL), grain number per spike (GNS), and thousand-grain weight (TGW) were measured after harvest. FHB responses were assayed under natural conditions in the 2005–2006 and 2006–2007 cropping seasons in Jianyang, Fujian province. Although no wheat is commercially produced in the area extremely severe FHB infections are common. Field management was the same as that for agronomic evaluations.
Sumai 3, Mianyang 26, and Yangmai 5 were used as the resistant, susceptible, and moderately susceptible controls, respectively. Racecadotril About 15 and 20 days after flowering, 30 spikes of each line were randomly selected. FHB severity in each spike was classified into five grades of symptoms on spikelets and spike rachi: 0 for no incidence on spikelets and spike rachis, 1 for ratio of incidence on spikelets less than 1/4 and no incidence on the rachis, 2 for ratio of incidence on spikelets between 1/4 and 1/2 and no incidence on the rachis, 3 for ratio of incidence on spikelets between 1/2 and 3/4 and incidence on spike rachis, 4 for ratio of incidence on spikelets of more than 3/4 or dead spikelets. , FHB disease index (DI) of each line was calculated as follows: DI = (Σ severity score of an individual spike × number of spikes)/(the highest severity score × total number of spikes).