玉米机械粒收破碎率高是影响粒收质量的重要因素，本试验利用研磨法测试玉米子粒破碎对水分的敏感性，探寻玉米子粒破碎率最低的含水率，并对品种耐破碎性进行评价。在北京和新乡两个试点分不同播期种植17个玉米品种，系统测试子粒水分动态变化，并利用研磨法同步进行子粒破碎率测试，分析破碎率与含水率的相关关系。北京试点和新乡试点及两地总体样本子粒含水率 (x) 与破碎率 (y) 关系均符合二次曲线 (y=ax²+bx+c) 关系，其中，两地512个样本拟合方程为y=0.0796x²-3.3929x+78.779(R²=0.2646，n=512) ，由方程拟合可见，最低破碎值为42.62%，对应的子粒含水率为21.31%；设置90%的置信区间，子粒破碎率最低的含水率范围为19.7%-22.3%，与田间机械粒收最低破碎率出现的含水率值一致。以破碎率值最低点为界发现，在低含水率条件下，破碎率与含水率呈显著线性负相关；在高含水率条件下，破碎率与含水率呈显著线性正相关；由拟合曲线(y=ax+b)斜率和相关度可见，在子粒高含水率条件下，子粒破碎对水分的敏感性更强，相关度更高。利用各品种子粒破碎率与含水率二次曲线的积分值评价不同品种子粒破碎敏感性评价方法，在北京试点筛选出耐破碎性强的品种为郑单958和丰垦139，易破碎品种包括联创825、吉单66、利单295和京农科728；在新乡试点筛选出耐破碎品种为禾田1号、郑单958和丰垦139，易破碎品种包括泽玉8911、迪卡653和京农科728。两地共用的6个品种分类结果基本一致。以上结果表明，研磨法是一种稳定性较高的检测方法，可以用于品种破碎对水分敏感性和耐破碎性评价，为耐破碎玉米品种的选育与筛选提供支持。

玉米田间籽粒收获相对于穗收能够节省后续运输、晾晒和脱粒等环节的人工成本，然而粒收后籽粒含水率出现升高的现象，降低了籽粒品质。为明确收获前后籽粒含水率差异的原因，本研究利用黄淮海平原多年多点玉米粒收试验以及在籽粒不同含水率阶段的分期收获试验，观测收获前、后籽粒含水率，破碎率，杂质率以及植株各器官含水率。在多年多点试验中，411组测试样本表明，粒收作业后籽粒含水率较收获前含水率值平均高出2.2%。分期收获试验结果表明，当收前籽粒含水率低于23.9%时，收获前、后测试结果没有显著差异，而当收前含水率高于23.9%后，收获后籽粒含水率测试值显著升高；收获后籽粒含水率增加值与收前籽粒含水率、破碎率、杂质率呈极显著正相关。通常，黄淮海夏玉米区收获期植株成熟度低、籽粒含水率高，造成较多的破碎和杂质，进而导致收获后籽粒含水率测试值升高。因此，我们建议选择生育后期植株落黄快的品种，并适当延迟收获期，降低收前籽粒含水率，从而降低破碎率和杂质率，提高收获后籽粒品质，推动中国玉米粒收发展。

Organic phosphorus (P) is an important component of the soil P pool, and it has been proven to be a potential source of P for plants.  The phosphorus utilization efficiency (PUE) and PUE related traits (tiller number (TN), shoot dry weight (DW), and root dry weight) under different phytate-P conditions (low phytate-P, 0.05 mmol L^–1 and normal phytate-P, 0.5 mmol L^–1) were investigated using a population consisting of 128 recombinant inbred lines (RILs) at the vegetative stage in barley.  The population was derived from a cross between a P-inefficient genotype (Baudin) and a P-efficient genotype (CN4027, a Hordeum spontaneum accession).  A major locus (designated Qpue.sau-3H) conferring PUE was detected in shoots and roots from the RIL population.  The quantitative trait locus (QTL) was mapped on chromosome 3H and the allele from CN4027 confers high PUE.  This locus explained up to 30.3 and 28.4% of the phenotypic variance in shoots under low and normal phytate-P conditions, respectively.  It also explains 28.3 and 30.7% of the phenotypic variation in root under the low and normal phytate-P conditions, respectively.  Results from this study also showed that TN was not correlated with PUE, and a QTL controlling TN was detected on chromosome 5H.  However, dry weight (DW) was significantly and positively correlated with PUE, and a QTL controlling DW was detected near the Qpue.sau-3H locus.  Based on a covariance analysis, existing data indicated that, although DW may affect PUE, different genes at this locus are likely involved in controlling these two traits.

The production of transgenic sweetpotato (cv. Xushu 18) plants exhibiting enhanced salt tolerance using salt overlysensitive (SOS) genes was achieved through Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strainEHA105 harbors a binary vector pCAMBIA3301 with SOS genes (SOS1, SOS2 and SOS3) and bar gene. Selection culturewas conducted using 0.3 mg L-1 phosphinothricin (PPT). A total of 40 plants were produced from the inoculated 170 cellaggregates via somatic embryogenesis. PCR analysis showed that 37 of the 40 regenerated plants were transgenic plants.The in vitro assay demonstrated that superoxide dismutase (SOD) and proline were significantly more accumulated andmalonaldehyde (MDA) was significantly less accumulated in 21 transgenic plants than in control plants when they wereexposed to 86 mmol L-1 NaCl. Salt tolerance of these 21 plants was further evaluated with Hoagland solution containing 0,51, 86, and 120 mmol L-1 NaCl in the greenhouse. The results indicated that 6 of them had significantly better growth androoting ability than the remaining 15 transgenic plants and control plants. Expression of SOS genes in the 6 salt-toleranttransgenic plants was demonstrated by RT-PCR analysis. This study provides an alternative approach for improving salttolerance of sweetpotato.