With the application of hybrid wheat, lodging is becoming one of the major factors limiting high yield in its production.  However, few studies have focused on combining ability and heterosis analysis of stem-related traits.  In this study, 24 crosses were made according to NCII genetic design, using the three (photo-sensitive male sterile lines)×eight (restorer lines) incomplete diallel crosses.  The length of basal second internode (LBSI) and breaking strength of basal second internode (BSBSI) as well as other stem-related traits were used to perform the principal component analysis (PCA), combining ability and heterosis analysis.  The PCA results showed that the variables could be classified into two main factors, which were named as the positive factor (factor 1) and the negative factor (factor 2), and accounted for 52.3 and 33.2%, respectively, of the total variance in different variables, combined with the analysis for index weight indicated that the factor 1-related traits play positive roles in lodging resistance formation of hybrids.  Combining ability variance analysis indicated that its genetic performance was mainly dominated by additive gene effects, and the hybrid combinations with higher lodging resistance can be selected by using of 14GF6085 (R1), 14GF6343-2 (R4), 14GF6937 (R6), 14GF7433-1 (R7), and BS1086 (M3), which are with the features with lower general combining ability (GCA) effects of factor 2-related traits whereas higher GCA effects of factor 1-related traits.  The heterosis analysis showed that the wide range of heterosis varied with the traits and combinations, and GCA or specific combining ability (SCA) effects of factor 1-related traits except wall thickness of basal second internode (WTBSI) were positively and closely related to the heterosis of lodging resistance.  Generally, the correlation coefficients of heterosis to GCA effects of sterile lines (GCA_m) of factor 1-related traits are significantly higher than that to GCA of restorer lines (GCA_r) and SCA, combined with the higher GCA_m variance values of factor 1-related traits compared to GCA_r, the GCA_m of factor 1-related traits should be particularly considered when breeding hybrid combinations.  The heritability analysis showed that the narrow-sense heritability of the diameter of basal second internode (DBSI) and the center of gravity height (TCGH) were obviously lower (<60%) than other traits, suggesting that these two traits were suitable for selection in higher generation for parental breeding.  These could provide a theoretical basis for parental breeding and heterosis utilization of lodging resistance. 

Because of the yield increase of 3.5–15% compared to conventional wheat, hybrid wheat is considered to be one of the main ways to greatly improve the wheat yield in the future.  In this study, we performed a principal component analysis (PCA) on two-line hybrids wheat and their parents using the grain weight (GW), the length of spike (LS), the kernel number of spike (KSN), and spike number (SPN) as variables.  The results showed that the variables could be classified into three main factors, the weight factor (factor 1), the quantity factor 1 (factor 2) and the quantity factor 2 (factor 3), which accounted for 37.1, 22.6 and 18.5%, respectively of the total variance in different agronomic variables, suggesting that the GW is an important indicator for evaluating hybrid combinations, and the grain weight of restorer line (RGW) could be used as a reference for parents selection.  The hybrid combination with a higher score in factor 1 direction and larger mid-parent heterosis (MPH) of the GW and its parents were used to carry out the analysis of grain filling, 1-aminocylopropane-1-carboxylicacid (ACC) and polyamine synthesis related genes.  The results suggested that the GW of superior grain was significantly higher than that of inferior grains in BS1453×JS1 (H) and its parents.  Both grain types showed a weight of H between BS1453 (M) and JS1(R), and a larger MPH, which may be caused by their differences in the active filling stage and the grain filling rate.  The ADP-glucose pyrophosphorylase (AGPase), granule bound starch synthase I (GBSSI), starch synthase III (SSS), and starch branching enzyme-I (SBE-I) expression levels of H were intermediated between M and R, which might be closely related to MPH formation of the GW.  Compared with R and H, the GW of M at maturity was the lowest.  The expression levels of spermidine synthase 2 (Spd2), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) had significantly positive correlations with the grain filling rate (r=0.77*, 0.51*, 0.59*), suggesting their major roles in the grain filling and heterosis formation.  These provide a theoretical basis for improving the GW of photo-thermo-sensitive male sterile lines (PTSMSL) by changing the endogenous polyamine synthesis in commercial applications.

Green manure use in China has declined rapidly since the 1980s with the extensive use of chemical fertilizers. The deterioration of field environments and the demand for green agricultural products have resulted in more attention to green manure. Human intervention and policy-oriented behaviors likely have large impacts on promoting green manure planting. However, little information is available regarding on where, at what rates, and in which ways (i.e., intercropping green manure in orchards or rotating green manure in cropland) to develop green manure and what benefits could be gained by incorporating green manure in fields at the county scale. This paper presents the conversion of land use and its effects at small region extent (CLUE-S) model, which is specifically developed for the simulation of land use changes originally, to predict spatial distribution of green manure in cropland and orchards in 2020 in Pinggu District located in Beijing, China. Four types of land use for planting or not planting green manure were classified and the future land use dynamics (mainly croplands and orchards) were considered in the prediction. Two scenarios were used to predict the spatial distribution of green manure based on data from 2011: The promotion of green manure planting in orchards (scenario 1) and the promotion of simultaneous green manure planting in orchards and croplands (scenario 2). The predictions were generally accurate based on the receiver operating characteristic (ROC) and Kappa indices, which validated the effectiveness of the CLUE-S model in the prediction. In addition, the spatial distribution of the green manure was acquired, which indicated that green manure mainly located in the orchards of the middle and southern regions of Dahuashan, the western and southern regions of Wangxinzhuang, the middle region of Shandongzhuang, the eastern region of Pinggu and the middle region of Xiagezhuang under scenario 1. Green manure planting under scenario 2 occurred in orchards in the middle region of Wangxinzhuang, and croplands in most regions of Daxingzhuang, southern Pinggu, northern Xiagezhuang and most of Mafang. The spatially explicit results allowed for the assessment of the benefits of these changes based on different economic and ecological indicators. The economic and ecological gains of scenarios 1 and 2 were 175 691 900 and 143 000 300 CNY, respectively, which indicated that the first scenario was more beneficial for promoting the same area of green manure. These results can facilitate policies of promoting green manure and guide the extensive use of green manure in local agricultural production in suitable ways.

(zeta)-carotene desaturase (ZDS) is a key enzyme for carotenoid biosynthesis, demonstrating high association with the yellow pigment (YP) content in wheat grain. Cloning ZDS gene and developing functional markers are important for marker-assisted selection in wheat breeding. In the present study, the full-length DNA sequence of a ZDS gene on wheat chromosome 2A, designated TaZds-A1, was cloned, with 14 exons and 13 introns, and it has an open reading frame (ORF) of 1 707 bp, encoding 568 amino acid residues. A co-dominant functional marker, YP2A-1, was designed based on the polymorphisms of two alleles at the locus, TaZds-A1a and TaZds-A1b, yielding 183- and 179-bp fragments in TaZds-A1a and TaZds-A1b genotypes, respectively. A new QTL for YP content was detected on chromosome 2A, co-segregating with the functional marker YP2A-1 and TaZds-A1; it explained 11.3% of the phenotypic variance for YP content in a doubled haploid (DH) population from Zhongyou 9507/CA9632. Among 217 Chinese wheat cultivars and advanced lines, the average grain YP content of 126 cultivars with TaZds-A1b allele was 7.8% higher than that of 91 cultivars with TaZds- A1a allele.