Male sterility of wheat-breeding line 337S (Triticum aestivum L.) is sensitive to both short day-length/low temperature and long day-length/high temperature. 337S was crossed with the common wheat variety, Huamai No. 8 and the F1 was highly fertile. The F2 population segregated in a 15:1 ratio for fertility/sterility in 243 individuals under long day-length/high-temperature. The two thermophotoperiod-responsive male sterile genes were mapped to chromosomes 5B and 2B using Simple Sequence Repeat (SSR) markers and bulked segregant analysis. Partial linkage maps around the sterility loci of chromosomes 2B and 5B were constructed using the 243 individuals in the F2 population. One gene (wptms1) for male sterility was flanked by the SSR markers Xgwm335 and Xgwm371 at a genetic distance in chromosome 5B of 4.1 and 24.4 cM, respectively. The second gene (wptms2) was mapped between markers Xgwm374 and Xgwm120 at a genetic distance of 6.6 and 20.9 cM, respectively. The closest linked markers Xgwm335 (wptms1) and Xgwm374 (wptms2) explained 53 and 38% of phenotypic variation for the fertility. The SSR markers provide a useful tool to transfer the male sterile genes into elite wheat germplasm.

The fertility of a wheat male sterile line 337S was investigated in 4 consecutive years with 18 different sowing dates. Line 337S showed high sterility under both short daylength/low temperature and long daylength/high temperature during ear development. It has 2 time windows to be used as a male sterile line for hybrid seed production. Its fertility rate can be >50% with suitable sowing time; thus, it can be self-maintained as a male sterile line. Line 337S was reciprocally crossed with 7 common wheat varieties and the fertility of their F1, F2, and BC1 hybrids was investigated at different sowing dates. The results showed that recessive nuclear genes controlled male sterility in 337S and no cytoplasmic effect was observed. All common wheat varieties were able to restore its fertility. The male sterility was controlled by a pair of recessive genes under short daylength/low temperature, but was governed by 2 pairs of recessive genes under long daylength/high temperature. This novel male sterile line provides a new tool for using heterosis in wheat.

Sinapis alba has many desirable agronomic traits including tolerance to drought. In this investigation, we performed the genome-wide transcriptional profiling of S. alba leaves under drought stress and rewatering growth conditions in an attempt to identify candidate genes involved in drought tolerance, using the Illumina deep sequencing technology. The comparative analysis revealed numerous changes in gene expression level attributable to the drought stress, which resulted in the down-regulation of 309 genes and the up-regulation of 248 genes. Gene ontology analysis revealed that the differentially expressed genes were mainly involved in cell division and catalytic and metabolic processes. Our results provide useful information for further analyses of the drought stress tolerance in Sinapis, and will facilitate molecular breeding for Brassica crop plants.

Maize is an important oil seed crop and a major food crop in different parts of the world.