Genetics Analysis And Molecular Mapping Of Basal Spikelets Sterile In Wheat

Basal spikelets sterile (BSS) is a common problem in wheat production and some commercial wheat cultivars are suffering serious basal spiekets sterile. We induce Shannong1186 using EMS and gain a mutant strain which basal spikelets are sterile (BSS). In this research we take BSS as experiment material and observe F1 & F2 segregation of BSS with Shannong1186 and Tainong18, of which basal spikelets are fertile, to analysis inheritance of gene controlling basal spikelets fertility. We map this gene using 180 F2 plants and their F3 strains of Shannong1186×BSS to analysis the gene's inheritance and molecular markersThe main results as follows:1. In all F1 plants of Shannong1186×BSS, BSS Shannong1186×Shannong1186, BSS Shannong1186×Tainong18 there is 0 or 1 spikelet sterile on the bottom of main spike, indicating that basal spikelet sterile is result from a recessive mutant gene. F2 plant of Shannong1186×BSS, BSS×Shannong1186 give 3:1 phenotypic segregation ratio, while BSS×Tainong18 fails. It tells us that there are at least two genes controlling fertility of basal spikelets. But inheritance of bss in Tainong18 is more complicated.2. Corelation analysis between agronomy traits are done with SAS software. No. of basal sterile spikelets positively correlate with plant height, but negative correlate with leaf width. No. of grain per ear is correlated with No. of fertile spikelets and top second leaf width, while negative correlated with sterile spikelets. All internode length and plant height correlates positively. All leaf width correlates positively. Leaf width negtively correlates with internode length and plant height.3. We adopt preferred small group method (PSG) to look for linkage maikers and find 9 markers on 4B will link with the gene controlling basal spikelets sterile (bss for short inafter here). In the map bss is 23.5 cM near a STS marker Mag2055.4. We screen QTL for variant traits of BSS on map of 4B construct in this study. Seven QTLs for plant height, top second internode length, top third internode length, top fifth internode length, flag leaf width, top second leaf width, top third leaf width and nuber of fertile spikelets are found in three intervals: SWES24-Mag2055, Wmc89-SWES24, SWES30-Wmc511.