小麦野生近缘植物冰草中蕴含许多对小麦遗传改良有利的基因。小麦-冰草2P异源易位系携带有小旗叶、小穗排列紧密、株型紧凑等特异性状。本文对携带有小麦-冰草不同2P易位片段的易位系及易位系回交群体进行农艺性状调查和遗传分析，结果表明，易位系2PT-3(2PL)易位片段具有促使旗叶长度变小的作用，易位系2PT-3(2PL)、2PT-5(2PL(0.6-1))易位片段具有促使旗叶宽度变小的作用。易位系2PT-13(2PS(0.18–0.36))易位片段具有增加旗叶的长度和面积的作用。易位系2PT-3(2PL)、2PT-8(2PL(0.86-1))易位片段具有促使小穗密度变大的作用。易位系2PT-7(2PL(0.0-0.09))、2PT-8(2PL(0.86-1))、2PT-10(2PS）、2PT-13(2PS(0.18-0.36))易位片段具有降低株高的作用。本研究可为小麦-冰草易位系的有效利用提供科学依据。

Founder parents have contributed significantly to the improvement of wheat breeding and production.  In order to investigate the genetic characteristics of founder parents and widely planted cultivars, Mazhamai (M), Biyumai (B) and six sibling lines (BM1–6) derived from the cross M×B were phenotyped for eight yield-related traits over multiple years and locations and genotyped using the the wheat 90K single nucleotide polymorphism (SNP) assay.  BM4 has been used as a founder parent, and BM1 has been widely planted, whereas BM2, 3, 5, and 6 have not been used extensively for breeding or planting in China.  Phenotypic comparisons revealed that BM4 and BM1 displayed a better overall performance than the other sibling lines.  BM1 showed higher thousand-grain weight than BM4, whereas BM4 exhibited lower coefficient of variation for most of the yield-related traits across different years and locations, indicating that BM4 was widely adaptable and more stable in different environments.  SNP analysis revealed that BM4 and BM1 inherited similar proportions of the M genome but are dissimilar to BM2, 3, 5, and 6.  Both BM1 and BM4 have specific alleles that differ from the other BM lines, and most of these alleles are concentrated in specific chromosomal regions that are found to associate with favorable QTLs, these SNPs and their surrounding regions may carry the genetic determinants important for the superior performance of the two lines.  But BM4 has more genetic diversity than BM1 with more specific alleles and pleiotropic regions, indicating that the genome of BM4 may be more complex than the other sibling lines and has more favorable gene resources.  Our results provide valuable information that can be used to select elite parents for wheat and self-pollinating crop breeding.

   Grain number per spike (GNPS) is a major factor in wheat yield breeding.  A new wheat germplasm Pubing 3504 shows superior features in spike traits.  To elucidate the genetic basis of spike and yield related traits in Pubing 3504, 282 F2:3 families were generated from the cross Pubing 3504×Jing 4839, and seven spike and yield related traits, including GNPS, spike length (SL), kernel number per spikelet (KPS), spikelet number per spike (SNS), thousand-grain weight (TGW), spike number per plant (SNP), and plant height (HT) were investigated.  Correlation analysis indicated significant positive correlations between GNPS and spike-related traits, including KPS, SNS, and SL, especially KPS.  A genetic map was constructed using 190 polymorphic simple sequence repeat (SSR), expressed sequence tag (EST)-SSR, and sequence-tagged-site (STS) markers.  For the seven traits measured, a total of 37 quantitative trait loci (QTLs) in a single-environment analysis and 25 QTLs in a joint-environment analysis were detected.  Additive effects of 70.3% (in a single environment) and 57.6% (in a joint environment) of the QTLs were positively contributed by Pubing 3504 alleles.  Five important genomic regions on chromosomes 1A, 4A, 4B, 2D, and 4D could be stably detected in different environments.  Among these regions, the marker interval Xmag834–Xbarc83 on the short arm of chromosome 1A was a novel important genomic region that included QTLs controlling GNPS, KPS, SNS, TGW, and SNP with stable environmental repeatability.  This genomic region can improve the spike trait and may play a key role in improving wheat yield in the future.  We deduced that this genomic region was vital to the high GNPS of Pubing 3504.

The wheat grain number per spike (GNPS) is a major yield-limiting factor in wheat-breeding programs. Germplasms with a high GNPS are therefore valuable for increasing wheat yield potential. To investigate the molecular characteristics of young spike development in large-spike wheat germplasms with high GNPS, we performed gene and protein expression profiling analysis with three high-GNPS wheat lines (Pubing 3228, Pubing 3504 and 4844-12) and one low-GNPS control variety (Fukuho). The phenotypic data for the spikes in two growth seasons showed that the GNPS of the three large-spike wheat lines were significantly higher than that of the Fukuho control line. The Affymetrix wheat chip and isobaric tags for relative and absolute quantitation-tandam mass spectrometry (iTRAQ-MS/MS) technology were employed for gene and protein expression profiling analyses of young spike development, respectively, at the floret primordia differentiation stage. A total of 598 differentially expressed transcripts (270 up-regulated and 328 down-regulated) and 280 proteins (122 up- regulated and 158 down-regulated) were identified in the three high-GNPS lines compared with the control line. We found that the expression of some floral development-related genes, including Wknox1b, the AP2 domain protein kinase and the transcription factor HUA2, were up-regulated in the high-GNPS lines. The expression of the SHEPHERD (SHD) gene was up-regulated at both the transcript and protein levels. Overall, these results suggest that multiple regulatory pathways, including the CLAVATA pathway and the meristem-maintaining KNOX protein pathway, take part in the development of the high-GNPS phenotype in our wheat germplasms.

Spike number is one of three yield-related factors and is closely related to wheat yield. In the present study, we found that the inhibited and normal tillers of the 3558 line presented phenotypic differences at the elongation stage by morphological and anatomical analysis. We then initiated a proteomic study using two-dimensional electrophoresis (2-DE) and nanoscale liquid chromatography-high-definition tandem mass spectroscopy, to isolate and identify the key proteins and metabolic pathways related to spike-development inhibition. A total of 31 differentially expressed proteins (DEPs), which were mainly involved in cell cycle regulation, photosynthesis, glycolysis, stress response, and oxidation-reduction reactions, were isolated and identified. 14-3-3-like proteins and proliferating cell nuclear antigen (PCNA), involved in cell-cycle regulation, were dramatically down-regulated in inhibited tillers compared to normal tillers. Six spots corresponding to degraded Rubisco large subunits, involved in photosynthesis, were detected in different locations of the 2-DE gels and were up-regulated in inhibited tillers. In addition, the relative levels of DEPs involved in glycolysis and oxidationreduction reactions changed dramatically. Development was blocked or delayed at the elongation stage in the inhibited tillers of 3558. Weakened energy metabolism might be one reason that the inhibited tillers could not joint and develop into spikes. These DEPs and related metabolic pathways are significant for understanding the mechanism of spike-development inhibition and studying the spike-development process in wheat.

The physical and chemical properties of the flours, starches, and modified starches of indica rice and japonica rice were investigated in this paper. Results showed that the swelling powers of flour, starch, and phosphate starch [substitution degree (DS)=0.065] of japonica rice were significantly higher than those (DS=0.065) of indica rice. The transmittance of modified starches was highest; and that of flours was lowest. The pasting property investigated with rapid visco analyzer (RVA) indicated that the peak viscosity and breakdown value of paste with high swelling power were high. Furthermore,the effect of protein and amylose content on pasting property were investigated. The results of rheological properties determined using rheological rheometer showed that at the same temperature, the storage modulus (G') of flour, starch,and modified starch of indica rice was higher than that of japonica rice. For each variety, the G' of flour was the highest,while the G' of modified starch was the lowest.