本研究评估了影响富平楸子再生及遗传转化体系的因素，发现富平楸子最佳再生体系为使用叶片为外植体，对叶片进行横切，近轴面贴近包含有MS、30 g L^-1蔗糖、8 g L^-1琼脂、5 mg L^-1 6-BA、2 mg L^-1 TDZ 和1 mg L^-1 NAA，pH为5.8的培养基上暗培养三周后见光培养，最佳遗传转化体系为在根癌农杆菌重悬液中侵染8min，然后进行4天共培养及3天延迟培养，并且使用150 mg L^-1头孢噻肟和15 mg L^-1卡那霉素作为筛选压。本研究建立了一套有效的富平楸子再生及遗传转化体系，通过此体系可快速获得富平楸子转基因材料，对苹果生物学研究具有重要意义。

2015-2017年连续2个生长季，选择西南地区广泛使用的小麦品种9个进行源库关系分析，其中3个具有不同株型品种进行花后源库操作处理：对照（Ct）、去除旗叶和倒二叶（Lr）和去除一侧小穗（Sr），设置2个施氮水平（N+, 150 kg ha^-1; N-, 60 kg ha^-1），研究两种氮水平下不同品种在冠层水平和单株水平上的源库关系。结果表明，Lr显著降低了3个品种的单粒重，而Sr使单粒重显著增加，表明小麦产量潜力在灌浆期受源限制较大，但源库平衡明显受气候变化和氮素亏缺的影响。籽粒产量与库容量（SICA）、粒数、生物量、SPAD值和叶面积指数呈显著正相关关系，表明源限制程度随着SICA的增加而增加。因此，当SICA增加时，育种家应更加关注源限制的影响，尤其在环境较好的条件下。川麦104属半紧凑型品种，穗子大小适中、上部叶片狭长，在源库平衡关系中表现较好，因为川麦104在Lr后籽粒重降幅小、Sr后籽粒重增幅大；花后干物质积累减少幅度最低、源库操作后灌浆期的光合产物向籽粒转移最多。

剪接因子Prp6是剪接三聚体U4/U6.U5中的关键蛋白，在人类细胞和裂殖酵母中，它也是调控前体mRNA剪接的激酶Prp4的底物。前期研究发现引起小麦赤霉病的禾谷镰孢菌FgPrp6蛋白序列的自发突变（角突变）可以部分恢复Fgprp4突变体的表型。禾谷镰孢菌FgPrp4激酶调控剪接效率，其敲除突变体生长缓慢且丧失产孢、有性生殖和致病能力。为了进一步探索FgPrp6与激酶FgPrp4的关系，本研究通过对随机收集的240株Fgprp4角突变子的FgPRP6基因进行PCR产物测序，鉴定了20个角变子中的12个突变。其中3个突变位点在FgPrp6蛋白的N端结构域和HAT重复结构域的连接处，7个突变位点位于前两个HAT重复区域。对角变子的转录组数据分析结果表明FgPrp6上不同位置的角突变对Fgprp4突变体前体mRNA剪接缺陷的恢复程度不同。通过在野生型菌株中转入FgPrp6^E308K-GFP载体或在内源FgPrp6上原位引入R230H突变，同时敲除FgPRP4的方法证实FgPrp6上的E308K或R230H都可以抑制Fgprp4。本研究利用co-IP和BiFc的方法证明禾谷镰孢菌的FgPrp6和激酶FgPrp4可以在体内互作，并进一步利用磷酸化抗体检测体内FgPrp6磷酸化水平的方法实验证明FgPrp6为FgPrp4的底物。通过将FgPrp6上保守的Prp4磷酸化位点和预测的磷酸化位点突变为A的方法验证这些位点的功能，结果表明T261，T219&T221和T199&T200对FgPrp6在菌落生长和有性生殖中的功能无关紧要，但是对其在侵染植物阶段的功能至关重要。扫描电镜和共聚焦显微镜观察发现它们主要在禾谷镰孢菌侵染生长，如侵染垫的形成和在植物细胞间的扩展中发挥作用。通过对野生型禾谷镰孢菌、Fgprp6/FgPRP6^Δ199-221-GFP或Fgprp6/FgPRP6^Δ250-262-GFP侵染三天的小麦麸片的转录组数据分析禾谷镰孢菌的前体mRNA剪接缺陷发现Fgprp6/FgPRP6^Δ199-221-GFP和Fgprp6/FgPRP6^Δ250-262-GFP菌株中各有28%和35%的内含子剪接具有缺陷，推测这种剪接缺陷是突变体侵染生长缺陷的原因。该研究为将来进一步解析禾谷镰孢菌前体mRNA剪接调控及剪接与致病性的关系奠定了基础。

多巴胺是一种儿茶酚胺和一种抗氧化剂，在应对逆境时起作用，它与植物激素相互作用以介导植物发育。目前，关于苹果中多巴胺功能的研究较少。本研究开发了一种用于分析苹果种质中的多巴胺测定方法，以阐明多巴胺在苹果树的组织分布、发育变化、昼夜变化和逆境响应。首先，对所提出的方法进行了验证，定量的线性范围在0.1-20 ng mL^-1范围内稳定，仪器、日间精密度和样品重复性相对标准偏差分别为1.024%、5.607%和7.237%，加标回收率大于100%，表明该方法的可行性及其适用于快速分析苹果属种质中的多巴胺。接下来，测量了322个苹果组织中的多巴胺含量。结果表明，苹果的多巴胺水平较低，叶片中多巴胺的平均含量高于果皮和果肉。多巴胺在栽培品种和野生种质中向右偏。最后，分析了组织特异性、发育变化、昼夜变化和对逆境的响应。在栽培品种‘皮诺娃’（Malus domestica）中，多巴胺含量在叶芽中最高，在果肉中最低。叶片和果肉中多巴胺含量随着栽培品种‘凉香’（Malus domestica）的生长发育而降低。与对照相比，干旱或盐胁迫后苹果叶片的多巴胺含量更高。在本研究中，建立了一种基于HPLC-MS的苹果多巴胺检测方法，并证明是一种稳健的方法。本研究为未来阐明苹果树中多巴胺的组织分布、发育变化、昼夜变化和逆境响应提供了一个框架。

In this paper, the influence of drought hardening on the growth, development, resistance physiology, leaf microstructure and stomatal behavior of potato seedlings under drought stress was studied, and the mechanism of drought hardening improvement of potato seedling drought resistance was elucidated.  We found that drought stress had several adverse effects on potato seedlings, yet drought hardening alleviated the decrease in relative water content (RWC), net photosynthetic rate (P_n) and chlorophyll content and inhibited the increase in relative electric conductivity and malondialdehyde (MDA) content.  Compared with contrast seedlings, drought-hardened seedlings also had enhanced root vigor, increased antioxidant enzyme activity and higher levels of abscisic acid (ABA), proline (Pro), soluble sugars and polyamines (PAs) under drought stress.  In addition, the stomatal density of potato seedling leaves increased significantly, while the leaf area, stomatal size and stomatal aperture decreased with drought hardening treatment.  These changes led to reduced leaf transpiration rate (T_r) and improved water utilization efficiency (WUE).  The changes in leaf microstructure also had a positive effect on the drought resistance of the drought-hardened potato seedlings. So it can be concluded that through increasing the content of some endogenous hormones, osmotic regulatory substances and the activities of antioxidant enzymes, the resistance physiology of drought-hardened potato seedlings was enhanced. 

   Understanding the morphological and physiological traits associated with improved filling efficiency in large-panicle rice varieties is critical to devise strategies for breeding programs and cultivation management practices. Information on such traits, however, remains limited. Two large-panicle varieties with high filled-grain percentage (HF) and two check large-panicle varieties with low filled-grain percentage (LF) were field-grown in 2012 and 2013. The number of spikelets per panicle of HF and LF both exceeded 300, and the filled-grain percentage (%) of HF was approximately 90, while that of LF was approximately 75 over the two years. The results showed that when the values were averaged across two years, HF yielded 12.9 t ha^–1, while LF yielded 11.0 t ha^–1. HF had a greater leaf area duration, biomass accumulation and transport of carbohydrates stored in the culm to the grains from heading to maturity compared with LF. HF exhibited a higher leaf photosynthetic rate, more green leaves on the culm, and higher root activity during filling phase, especially during the middle and late filling phases, in relative to LF. The length of HF for upper three leaves was significantly higher than that of LF, while the angle of upper three leaves on the main culm was less in both years. Meanwhile, specific leaf weight of HF was significantly higher when compared with LF. In addition, the grain filling characteristics of HF and LF were investigated in our study. Our results suggested that a higher leaf photosynthetic rate and root activity during filling phase, greater biomass accumulation and assimilate transport after heading, and longer, thicker and more erect upper three leaves were important morphological and physiological traits of HF, and these traits could be considered as selection criterion to develop large-panicle varieties with high filled-grain percentage.

   Good crop stand establishment and root system development are essential for optimum grain yield of dryland wheat (Triticum aestivum L.). At present, little is known about the effect of tillage and straw mulch on the root system of wheat under dryland areas in southwestern China. The aim of this study was to evaluate the effect of three tillage treatments (no-till, NT; rotary till, RT; conventional till, CT) and two crop residue management practices (straw mulch, ML; non-straw mulch, NML) on stand establishment, root growth and grain yield of wheat. NT resulted in lower soil cover thickness for the wheat seed, higher number of uncovered seeds, lower percentage of seedling-less ridges and lower tiller density compared to RT and CT; ML resulted in higher tiller density compared to NML. Straw mulching resulted in more soil water content and root length density (RLD) at most of the growth stages and soil depths. The maximum RLD, root surface area density and root dry matter density were obtained under NT. In the topmost 10 cm soil layer, higher RLD values were found under NT than those under RT and CT. There were no significant differences in the yield or yield components of wheat among the tillage treatments in 2011–2012, but NT resulted in a significant higher yield compared to RT and CT in 2012–2013. Grain yield was significantly higher in ML compared to in NML. A strong relationship was observed between the water-use efficiency and the grain yield. Both NT and ML proved beneficial for wheat in term of maintaining higher tiller density, better soil water status and root growth, leading to a higher grain yield and enhanced water-use efficiency, especially in a low rainfall year.

High-temperature stress (HTS) at the grain-filling stage in spring maize (Zea mays L.) is the main obstacle to increasing productivity in the North China Plain (NCP). To solve this problem, the physiological mechanisms of HTS, and its causes and impacts, must be understood. The HTS threshold of the duration and rate in grain filling, photosynthetic characteristics (e.g., the thermal stability of thylakoid membrane, chlorophyll and electron transfer, photosynthetic carbon assimilation), water status (e.g., leaf water potential, turgor and leaf relative water content) and signal transduction in maize are reviewed. The HTS threshold for spring maize is highly desirable to be appraised to prevent damages by unfavorable temperatures during grain filling in this region. HTS has negative impacts on maize photosynthesis by damaging the stability of the thylakoid membrane structure and degrading chlorophyll, which reduces light energy absorption, transfer and photosynthetic carbon assimilation. In addition, photosynthesis can be deleteriously affected due to inhibited root growth under HTS in which plants decrease their water-absorbing capacity, leaf water potential, turgor, leaf relative water content, and stomatal conductance. Inhibited photosynthesis decrease the supply of photosynthates to the grain, leading to falling of kernel weight and even grain yield. However, maize does not respond passively to HTS. The plant transduces the abscisic acid (ABA) signal to express heat shock proteins (HSPs), which are molecular chaperones that participate in protein refolding and degradation caused by HTS. HSPs stabilize target protein configurations and indirectly improve thylakoid membrane structure stability, light energy absorption and passing, electron transport, and fixed carbon assimilation, leading to improved photosynthesis. ABA also induces stomatal closure to maintain a good water status for photosynthesis. Based on understanding of such mechanisms, strategies for alleviating HTS at the grain-filling stage in spring maize are summarized. Eight strategies have the potential to improve the ability of spring maize to avoid or tolerate HTS in this study, e.g., adjusting sowing date to avoid HTS, breeding heat-tolerance varieties, and tillage methods, optimizing irrigation, heat acclimation, regulating chemicals, nutritional management, and planting geometric design to tolerate HTS. Based on the single technology breakthrough, a comprehensive integrated technical system is needed to improve heat tolerance and increase the spring maize yield in the NCP.  

Late-maturity type of Yongyou japonica/indica hybrids series (LMYS) have shown great yield potential, and are being widely planted in the lower reaches of Yangtze River, China. Knowledge about suitable growing zone and evaluation of yield advantage is of practical importance for LMYS in this region. Fifteen LMYS, two high-yielding inbred japonica check varieties (CK-J) and two high-yielding hybrid indica check varieties (CK-I) were grown at Xinghua (119.57°E, 33.05°N) of Lixiahe region, Yangzhou (119.25°E, 32.30°N) of Yanjiang region, Changshu (120.46°E, 31.41°N) of Taihu Lake region, and Ningbo (121.31°E, 29.45°N) of Ningshao Plain in 2013 and 2014. The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6, 14 and 15 LMYS were mature before the secure maturity date at Yangzhou, Changshu and Ningbo, respectively. One variety was identified as high-yielding variety among LMYS (HYYS) at Yangzhou, 8 HYYS in 2013 and 9 HYYS in 2014 at Changshu, 9 HYYS at Ningbo. HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8% higher grain yield than both CK-J and CK-I at each experimental site. Grain yield of HYYS at each experimental site was about 12.0 t ha–1 or higher, and was significantly higher than CK varieties. High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle. Plant height of HYYS was about 140 cm, and was significantly higher than check varieties. Significant positive correlations were recorded between duration from heading to maturity stage and grain yield, and also between whole growth periods and grain yield. HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage. Comprehensive consideration about safe maturity and yield performance of LMYS at each experimental site, Taihu Lake region (representative site Changshu) and Ningshao Plain (representative site Ningbo) were thought suitable growing zones for LMYS in the lower reaches of Yangtze River. The main factors underlying high yield of HYYS were larger sink size, higher plant height, longer duration from heading to maturity stage and whole growth periods, and higher biomass accumulation and leaf area duration during grain filling stage.

Plants that grow well while accumulating and transporting less potassium (K) perform better than more-sensitive plants when under deficiency conditions, which makes low-K-input and environmentally friendly agriculture possible. We conducted hydroponics and sand culture experiments to evaluate the efficiency of various apple (Malus domestica Borkh) rootstocks in their K uptake and utilization. Five genotypes were selected which are widely used in China -M. hupehensis Rehd, M. prunifolia Borkh, M. robusta Rehd, M. sieversii Roem, and M. rockii Rehd. Plant heights, root and shoot dry weights, and K concentrations were recorded. These genotypes differed markedly in dry weights, absolute and relative K concentrations, absolute and relative K accumulations, and their K efficiency ratio under deficient K conditions. The last parameter, expressed as relative shoot dry weight, was strongly and positively correlated with the other four parameters in each genotype. Therefore, we suggest that this parameter could serve as an index when selecting K-efficient genotypes. In this study, we have determined that M. sieversii and M. rockii are K-inefficient genotypes; M. prunifolia is K-efficient genotype; M. hupehensis and M. robusta have moderate levels of potassium efficiency.

We evaluated the effects of neutral detergent soluble fiber (NDSF) and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC). The experiment had a 2×2 factorial design with two dosages of sucrose, low (ca. 0.26 g d-1, low-sucrose) and high (ca. 1.01 g d-1, high-sucrose), and two dosages of supplied NDSF, low (1.95 g d-1, low-NDSF) and high (2.70 g d-1, high-NDSF). Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber (NDF) and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSF×sucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solidassociated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcus flavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies of R. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.

High temperature stress (HTS) on spring maize (Zea mays L.) during the filling stage is the key factor that limits the yield increase in the North China Plain (NCP). Subsoiling (SS) and ridge tillage (R) were introduced to enhance the ability of spring maize to resist HTS during the filling stage. The field experiments were conducted during the 2011 and 2012 maize growing seasons at Wuqiao County, Hebei Province, China. Compared with rotary tillage (RT), the net photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll relative content (SPAD) of maize leaves was increased by 40.0, 42.6, 12.8, and 29.7% under SS, and increased by 20.4, 20.0, 5.4, and 14.2% under R, repectively. However, the treatments reduce the intercellular CO2 concentration under HTS. The SS and R treatments increased the relative water content (RWC) by 11.9 and 6.2%, and the water use efficiency (WUE) by 24.3 and 14.3%, respectively, compared with RT. The SS treatment increased the root length density and soil moisture in the 0-80 cm soil profile, whereas the R treatment increased the root length density and soil moisture in the 0-40 cm soil profile compared with the RT treatment. Compared with 2011, the number of days with temperatures 33°C was more 2 d and the mean day temperature was higher 0.9°C than that in 2012, whereas the plant yield decreased by 2.5, 8.5 and 10.9%, the net photosynthetic rate reduced by 7.5, 10.5 and 18.0%, the RWC reduced by 3.9, 5.6 and 6.2%, and the WUE at leaf level reduced by 1.8, 5.2 and 13.1% in the SS, R and RT treatments, respectively. Both the root length density and the soil moisture also decreased at different levels. The yield, photosynthetic rate, plant water status, root length density, and soil moisture under the SS and R treatments declined less than that under the RT treatment. The results indicated that SS and R can enhance the HTS resistance of spring maize during the filling stage, and led to higher yield by directly improving soil moisture and root growth and indirectly improving plant water status, photosynthesis and grain filling. The study can provide a theoretical basis for improving yield of maize by adjusting soil tillage in the NCP.

Synthetic hexaploid wheat (SHW) represents a valuable source of new resistances to a range of biotic and abiotic stresses. A recombinant inbred line (RIL) population with 127 recombinant inbred lines derived from a SHW-derived variety Chuanmai 42 crossing with a Chinese spring wheat variety Chuannong 16 was used to map QTLs for agronomic traits including grain yield, grains per square meter, thousand-kernel weight, spikes per square meter, grain number per spike, grains weight per spike, and biomass yield. The population was genotyped using 184 simple-sequence repeat (SSR) markers and 34 sequence-related amplified polymorphism (SRAP) markers. Of 76 QTLs (LOD>2.5) identified, 42 were found to have a positive effect from Chuanmai 42. The QTL QGy.saas-4D.2 associated with grain yield on chromosome 4D was detected in four of the six environments and the combined analysis, and the mean yield, across six environments, of individuals carrying the Chuanmai 42 allele at this locus was 8.9% higher than that of those lines carrying the Chuannong 16 allele. Seven clusters of the yield-coincident QTLs were detected on 1A, 4A, 3B, 5B, 4D, and 7D.