Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.     

灌水对强筋小麦籽粒产量及营养品质的影响

为明确水地强筋冬小麦高产、优质、高效的灌溉技术，试验设3个灌水时期8个灌溉处理［越冬期灌1水（W₁），拔节期灌1水（W₂），孕穗期灌1水（W₃），越冬期和拔节期灌2水（W₁₂），越冬期和孕穗期灌2水（W₁₃），拔节期和孕穗期灌2水（W₂₃），越冬期、拔节期和孕穗期灌3水（W₁₂3），全生育期不灌水处理（CK）］,于小麦成熟期测定籽粒产量、总蛋白及其组分含量和淀粉含量。结果表明，与不灌水的CK比较，所有灌水处理的籽粒产量、有效穗数、穗粒数、千粒重、蛋白质产量以及籽粒淀粉含量均显著增加，但籽粒的总蛋白及其组分含量均呈不同程度降低（W₁处理除外）。越冬期灌水对有效穗数、籽粒产量、总蛋白及其组分含量、淀粉含量的提升作用较大；拔节期灌水对穗粒数的提升作用较大，但对淀粉含量的提升作用较小，对总蛋白及其组分含量的降低作用较大；孕穗期灌水对千粒重的提升作用较大，对蛋白质产量的提升作用较小。随着灌水次数增加，小麦籽粒产量显著提高，淀粉含量先显著提高后基本不变，而籽粒总蛋白及其组分含量降低。W₁₂3处理籽粒产量最高，其次是W₁₃处理；W₁处理籽粒蛋白质及其组分含量最高，其次是W₁₂及W₁₃处理；W₂₃处理淀粉含量最高，其次是W₁₂或W₁₃处理。综合各项指标，最好的灌水组合是越冬期和孕穗期灌2水（W₁₃）。     

养猪场沼渣制备包膜缓释肥理化性质表征

文章以分散式养猪场沼渣为应用研究对象,以8%聚乙烯醇为包膜材料,改性斜发沸石为肥料载体和缓控释材料调理剂,通过添加不同沸石量制备3种复混包膜缓释肥。利用红外光谱、扫描电镜及三维荧光对3种缓释肥的进行表征。结果表明:添加改性沸石的复混包膜肥除了增加显著的沸石红外特征谱外,其余红外光谱图差异不明显,表明添加沸石对有机质(富里酸和腐殖酸)结构和化学键型并未产生明显的影响,即不影响沼渣理化性质;添加改性沸石可以使聚乙烯醇完整的覆盖在肥料表面,膜壳更加平整光滑,膜层更加致密;三维荧光光谱显示复混包膜肥Ⅰ浸出富里酸和腐殖酸浓度最大,复混包膜肥Ⅲ浓度最低,表明添加沸石有减缓肥料养分释放的效果。该研究对于利用养猪场沼渣制备包膜缓释肥有一定的参考价值。     

水分与氮素及其互作对水稻产量和水肥利用效率的影响研究进展

了解水分、氮素及其互作对水稻产量与水、氮利用效率的影响,对协同提高水稻产量与水氮利用效率有重要意义。本文概述了水稻节水灌溉技术、氮肥利用效率与氮肥施用技术、水分与氮素对水稻产量及水氮利用效率的耦合效应、作物-土壤关系及水氮调控机制等方面取得的进展;讨论了存在的问题,这些问题包括:高产水稻作物与土壤的水氮互作效应尚不明确;高产水稻水氮耦合与高效利用的分子机理不清楚;协同提高水稻产量与水氮利用效率的调控途径尚未掌握。针对这些问题,建议今后重点研究:高产水稻作物与土壤的水氮互作效应及其机制;水氮互作调控水稻吸收利用水分和氮素的生理与分子机理;协同提高水稻产量和水氮利用效率的调控途径与关键技术。     

8株优良大豆根瘤菌与不同地区27个大豆主栽品种的匹配性研究

大豆是我国重要的油料作物和高蛋白粮饲兼用作物,具有与根瘤菌共生固氮的能力。近十几年来,我国大豆品种更新快,导致大豆根瘤菌株与新品种匹配能力差、接种效果不明显。筛选与主栽大豆品种匹配性好、固氮效率高的广谱性优良菌株,可为针对性的施用大豆根瘤菌接种剂提供菌种资源和方案。选取本实验室前期分离保存的6个优良快生型大豆根瘤菌株和2个慢生型大豆根瘤菌株,在砂培盆栽条件下与不同地区的27个大豆主栽品种进行匹配试验。测定分析了植株地上部分生物量、高度、根瘤数量、根瘤生物量和根瘤固氮酶活指标。结果表明:不同大豆根瘤菌之间结瘤固氮能力存在极显著的差异;供试根瘤菌均能够与国内24个大豆品种结瘤,广谱性较好;植株地上部分高度、根瘤数量、根瘤生物量和根瘤固氮酶活与地上部分生物量呈显著相关;大部分接种根瘤菌后的植物生物量显著高于CK;HN01、GR3、HH29、HH103匹配性和固氮效率均不逊色于USDA110,具有在东北地区、黄淮海地区、长江流域、东南地区推广的潜能;从品种来看,中豆39、BD2、天隆1号与8株供试大豆根瘤菌的匹配接种表现出高生物量特点。此外,本文还筛选出大豆-大豆根瘤菌的表型最佳匹配组合中豆39-GR3,适合长江流域地区;同样筛选到东北地区、黄淮海地区、东南地区最佳匹配组合,分别是HN01-辽豆14、HN01-徐豆14、HN01-BD2。本文初步建立了优良根瘤菌与大豆主栽品种的匹配关系,为在田间试验中进一步筛选和应用这些优良菌株提供了材料和指导。     

氮磷钾用量对小麦冠层不同层次光截获和干物质分配的影响

为明确不同氮、磷、钾用量对小麦冠层不同层次光截获和干物质分配的影响，以济麦22为供试材料，设置F0（不施肥）、F1（N 180 kg·hm^-2，P₂O₅ 75 kg·hm^-2，K₂O 60 kg·hm^-2）、F2（N 225 kg·hm^-2，P₂O₅ 120 kg·hm^-2，K₂O 105 kg·hm^-2）和F3（N 270 kg·hm^-2，P₂O₅ 165 kg·hm^-2，K₂O 105 kg·hm^-2）4个施肥量处理，比较分析开花后不同氮、磷、钾用量对小麦叶面积指数、冠层不同层次光截获特性和成熟期干物质分配的影响。结果表明，F1处理下叶面积指数显著高于F0处理，而与F2和F3处理间无显著差异；开花后15 d，F1处理下小麦冠层不同层次及总PAR截获率和截获量均显著高于F0处理，而与F2和F3处理间无显著差异。F1处理下成熟期干物质在小麦冠层不同层次营养器官中的分配量、籽粒中的分配量及总干物质积累量显著高于F0处理，而与F2和F3处理间无显著差异。成熟期干物质在小麦冠层不同层次营养器官和籽粒中的分配量以及总干物质积累量与冠层上层（顶部至株高2/3）、中层（株高2/3至株高1/3）和总PAR截获率均呈显著正相关。F1处理（N 180 kg·hm^-2，P₂O₅ 75 kg·hm^-2，K₂O 60 kg·hm^-2）为本试验条件下的最优处理。     

智慧图书馆微观知识生态系统运行机理研究

伴随多元化时代的来临,用户的知识需求日益多元化、专业化,对图书馆服务提出了新的挑战。对智慧图书馆微观知识生态系统运行机理的研究,能够为新型知识服务提供理论基础,保障知识资源进行有效的优化整合,实现服务升级。文章在简要分析智慧图书馆微观知识生态系统四大要素的基础上,着重从社会发展、技术进步,知识富集、优化调整和需求驱动、服务升级三方面探讨其形成动因,重点分析智慧图书馆微观知识生态系统的生命周期,最后从合作、循环和保障三方面探讨其运行机理。     

An investigation on the effect of heat-moisture treatment on baking quality of wheat by using response surface methodology

Effect of heat-moisture treatment on quality properties of two bread wheats (cvs. Tosunbey and Bayraktar) were investigated by using response surface methodology (RSM). Temperature and moisture conditions in the experimental design were in the range of 55–95 °C and 13–19%. Heat-moisture treated grains were milled into flour and quality properties were determined. The optimum moisture-temperature combination for the highest dry gluten, Zeleny sedimentation, Alveograph W and bread volume values were estimated as 14%-63 °C for Tosunbey and 19%-55 °C for Bayraktar samples. Alveograph W seems to be a good indicator of baking quality for wheats treated at higher temperatures. In order to describe the relationship between the dependent and independent variables (moisture, temperature), the response values were fitted by second order polynomial models. Significance analysis showed that the effect of both moisture and temperature on dry gluten content, sedimentation and falling number values for Tosunbey; falling number and damaged starch values for Bayraktar were significant (p < 0.05). The effect of temperature on Farinograph water absorption, W and P/G, bread volume and firmness values were significant for both cultivars (p < 0.05). It can be concluded that improvement in baking quality can be achieved and flours with different properties can be produced by heat-moisture treatments on wheat.     

耕作方式及秸秆还田对土壤性质、微生物碳源代谢及小麦产量的影响

以小麦品种济麦22为试验材料,采用裂区试验设计,耕作方式为主区,分别设常规翻耕(C)、深松(S)、旋耕(R)处理,副区为秸秆还田量,分别设秸秆全还田(P)和秸秆不还田(A)处理,采用Biolog Eco技术测定土壤微生物碳源代谢功能,并分析土壤基本理化性质和作物产量。结果显示:深松与秸秆还田均有利于土壤含水量和有机碳含量的提高,0～15 cm土层分别提高了9.78%和24.00%,15～30 cm土层分别提高了7.08%和15.81%;深松提高了15～30 cm土层的pH值6.67%,秸秆还田提高了0～15 cm土层的pH值4.32%。深松和秸秆还田均有利于代谢多样性(丰富度指数、香浓多样性指数)、碳源代谢强度的提高,0～15 cm土层分别提高了26.84%、3.84%和38.02%,15～30 cm土层分别提高了11.87%、 3.63%和14.74%。主成分分析表明常规翻耕秸秆不还田和旋耕耕作秸秆不还田碳源代谢功能相近,15～30 cm层次内常规翻耕秸秆全还田碳源代谢功能和深松耕作秸秆全还田处理相近。深松和秸秆还田平均提高了小麦产量5.82%,微生物碳源代谢功能与小麦产量具有极显著的相关性。     

The M43 domain-containing metalloprotease RcMEP1 in Rhizoctonia cerealis is a pathogenicity factor during the fungus infection to wheat

Wheat(Triticum aestivum L.) is an important staple crop for global human. The necrotrophic fungus Rhizoctonia cerealis is the causal pathogen of sharp eyespot, a devastating disease of wheat. Herein, we identified RcMEP1, a zinc metalloproteaseencoding gene from R. cerealis genomic sequences, and characterized its pathogenesis function. RcMEP1 expressed at markedly-high levels during R. cerealis infection process to wheat. The predicted protein RcMEP1 comprises of 287 amino acid residues and contains a signal peptide and a M43 metalloprotease domain harboring the active site motif(HEVGHWLGLYH). The assays of Agrobacterium tumefaciens-mediated transient expression in Nicotiana benthamiana leaves indicated that RcMEP1 is an apoplastic elicitor of cell death, and that the predicted signal peptide functions and is required for secretion and cell death-induction. The purified RcMEP1 protein and its M43 domain peptide were individually able to induce plant cell death and H2 O2 accumulation, and to inhibit expression of host chitinases when infiltrated into wheat and N. benthamiana leaves, while the M43 domain-deleting peptide and negative control lacked the capacity. Moreover, compared with the control pretreatment, the purified RcMEP1 protein or its M43-domain peptide resulted in enhanced pathogenesis in the inoculated wheat, whereas the M43 domain-deleting peptide failed. These results suggest that RcMEP1 acted as an important pathogenicity factor during R. cerealis infection to wheat and that its signal peptide and M43 domain are required for the secretion and pathogenesis of RcMEP1. This study provides insights into pathogenesis role of M43 domain-containing metalloproteases during R. cerealis infection to wheat.