Molecular genetic analysis of five spike-related traits in wheat using RIL and immortalized F2 populations

Abstract

Kernel number per spike is one of the most important yield components of wheat. To map QTLs related to kernel number including spike length (SPL), spikelet number per spike (SPN), fertile spikelet number (FSPN), sterile spikelet number (SSPN) and compactness, and to characterize the inheritance modes of the QTLs and two-locus interactions, 136 recombinant inbred lines (RILs) derived from 'Nanda2419' x 'Wangshuibai' and an immortalized F(2 )population (IF(2)) generated by randomly permutated intermating of these RILs were investigated. QTL mapping made use of the previously constructed over 3300 cM linkage map of the RIL population. Three, five, two, two and six chromosome regions were identified, respectively, for their association with SPL, SPN, FSPN, SSPN, and compactness in at least two of the three environments examined. All compactness QTLs but one shared the respective intervals of QSpn.nau-5A and the SPL QTLs. Xcfd46-Xwmc702 interval on chromosome 7D was related to all traits but SSPN and had consistently the largest effects. The fact that not all the compactness QTL intervals were related to both SPL and SPN indicates that compactness is regulated by different mechanisms. Interval coincidence between QTLs of SPL and SPN and between QTLs of FSPN and SSPN was minimal. For all the traits, favorable alleles exist in both parents. Inheritance modes from additiveness to overdominance of the QTLs were revealed and two-locus interactions were detected, implying that the traits studied are under complex genetic control. The results could contribute to wheat yield improvement and better use of Wangshuibai and Nanda2419 the two special germplasms in wheat breeding program.

Quantitative Trait Loci for Grain Yield and Adaptation of Durum Wheat (Triticum durum Desf.) Across a Wide Range of Water Availability

“…Comparative analysis with the known major QTL for yield in wheat: A survey of the literature reporting QTL for GY and related agronomic traits in both tetraploid and hexaploid wheat (Li et al 2002;Peng et al 2003;Elouafi and Nachit 2004;Huang et al 2004Huang et al , 2006McCartney et al 2005;Quarrie et al 2005Quarrie et al , 2007Marza et al 2006;Narasimhamoorthy et al 2006;Kuchel et al 2007;Kumar et al 2007;Ma et al 2007) revealed rather different scenarios for the two major GY QTL identified in our study. Our comparative analysis was carried out by relating the (LOD À 1) supporting interval of the QTL to the Ta-SSR-2004 consensus map (Somers et al 2004).…”

Genetic associations in the detection of QTLs for wheat spike-related traits

“…This trait has attracted great interest in recent studies due to its importance in avoiding ear diseases. Grain number per spike is one of the most important yield components of wheat (Ma et al, 2007), which was associated with the largest number of markers evaluated, i.e., five (Table 5). The specific marker for grain number was barc101 (2BL), which has not been previously associated with this trait, indicating the presence of a new QTL.…”

“…The presence of QTLs near marker gwm11 for a large number of agronomic and adaptive traits has been proven by Wang et al (2009), whereas, in the present study, the only association of this marker was found with sterile spikelets per spike. Only a limited number of QTL studies for sterile spikelet number per spike have been documented (Ma et al, 2007). The coefficient of variation for sterile spikelets per spike obtained by descriptive statistics was extremely high (Table 6), probably due to the selection of a relatively small number of varieties with branched architecture of wheat spikes.…”

“…The analyses of the genetic control of spike-related characteristics and of individual effects of different genes and quantitative trait loci (QTL) could provide specific information and be useful for indirect determination of yield improvement (Ma et al, 2007). In the last few years, association mapping has been considered one of the most promising methods for the exploration of the entire genome in the search of preferred chromosome regions, QTLs, and desired genes (Liu et al, 2010).…”

Descriptive statistics and correlation analysis of agronomic traits in a maize recombinant inbred line population

“…Of course, these populations are associated with longer time commitments and higher costs for population construction than F 2 and backcross populations (Wan et al, 2008). Currently, the studies using an RIL as a mapping population are focused on a few crops, including rice (Wan et al, 2006), soybean (Fu et al, 2006), and wheat (Ma et al, 2007). Only limited reports were found in maize in the literature (Bouchez et al, 2002;Ordas et al, 2008), especially in China (Ding et al, 2008).…”