Screening and identification of soybean varieties with high phosphorus efficiency at seedling stage

In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X₁),relative value of root P utilization efficiency(X₂),and root volume(X₃)under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X₁t 0.320X₂t 0.007X₃-0.664(P=0.000,R²=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.     

光照对箭筈豌豆及其子代生长和繁殖特性的影响

光照不仅会影响植物自身的生长,也可能会对其子代的生长具有潜在作用。以箭筈豌豆品种兰箭1号和兰箭3号为材料,分析遮荫和自然光照下箭筈豌豆及其子代的生长特性。结果表明:光照对箭筈豌豆生长和繁殖特性的影响因基因型而异。与光照条件相比,遮荫显著降低兰箭1号生物量及茎叶比,但对繁殖分配的比例影响不显著。与此相反,遮荫对兰箭3号的生长与繁殖无显著影响;母本光照环境对箭筈豌豆子代生长特性具有一定程度的影响,且这种影响因子代植株生长的光照环境而异。当子代在遮荫环境下,母本环境显著影响兰箭1号分枝数、地上生物量、总生物量、地上/地下生物量以及兰箭3号的分枝数。但当子代在光照环境下生长时,除兰箭3号分枝数外,其他生长特性均不受母本环境影响。     

Carbohydrate and crude protein fractions in perennial ryegrass as affected by defoliation frequency and nitrogen application rate

The objective of this study was to evaluate the effects of defoliation frequency (either at two‐ or three‐leaf stage) and nitrogen (N) application rate (0, 75, 150, 300, 450 kg N ha^?1 year^?1) on herbage carbohydrate and crude protein (CP) fractions, and the water‐soluble carbohydrate‐to‐protein ratio (WSC:CP) in perennial ryegrass swards. Crude protein fractions were analysed according to the Cornell carbohydrate and protein system. Carbohydrate fractions were analysed by ultra‐high‐performance liquid chromatography. Sward defoliation at two‐leaf stage increased the total CP, reduced the buffer‐soluble CP fractions and decreased carbohydrate fractions of herbage (P < 0·001). The effect of defoliation frequency was less marked during early spring and autumn (P < 0·001) than for the rest of the seasons. An increase in N application rate was negatively associated with WSC, fructans and neutral detergent fibre (P < 0·001), and positively associated with CP and nitrate (N‐NO₃) contents of herbage. Nitrogen application rate did not affect CP fractions of herbage (P > 0·05). The fluctuations in CP and WSC contents of herbage resulted in lower WSC:CP ratios during early spring and autumn (0·45:1 and 0·75:1 respectively) than in late spring (1·11:1). The herbage WSC:CP ratio was greater (P < 0·001) at the three‐leaf than the two‐leaf defoliation stage and declined as the N application increased in all seasons (P < 0·001). The results of this study indicate that CP and carbohydrate fractions of herbage can be manipulated by sward defoliation frequency and N application rate. The magnitude of these effects, however, may vary with the season.     

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）。     

不同基因型燕麦苗期耐盐碱性分析 及其鉴定指标的筛选

为探讨不同基因型燕麦苗期的耐盐碱性，筛选适宜松嫩平原种植的燕麦品种，本研究采用Hoagland营养液水培法，以250 mmol·L^-1高浓度NaHCO₃胁迫模拟松嫩平原盐碱环境，对49份来自国内外不同地区的主栽燕麦品种进行研究。试验测定了250 mmol·L^-1 NaHCO₃胁迫下燕麦的株高（X₁）、根长（X₂）、地上部鲜重（X₃）、地下部鲜重（X₄）、地上部干重（X₅）、地下部干重（X₆）、地上部含水量（X₇）、地下部含水量（X₈）、根冠比（X₉）9个指标，以各单项指标的耐盐碱系数(SATC) 作为衡量耐盐碱性的依据，利用多元分析方法对不同燕麦品种耐盐碱能力进行了综合评价。结果表明：通过对各指标的耐盐碱系数进行主成分分析，得到X₄、X₇、X₈ 3个综合指标，涵盖了全部数据86.155%的信息量；通过隶属函数分析和聚类分析将49份燕麦品种分为3类，其中草莜1号、张燕7、T7等3个品种为耐盐碱品种，HLJ 1、白燕2号等41个品种为中度耐盐碱品种，三分三、坝莜13号等5个品种为盐碱敏感品种。     

Source of mycorrhizal inoculum influences growth of Faidherbia albida seedlings

Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.     

利用SOM聚类分析及主成分分析方法鉴定小麦品种萌发期耐盐性

为了研究不同小麦品种萌发期的耐盐性,为小麦萌发期耐盐性鉴定提供快速、准确的鉴定方法和理论依据。本研究以40个冬小麦品种为试验材料,通过主成分分析法(PCA)与神经网络自组织映射(SOM)聚类分析法,研究盐胁迫对40个小麦品种萌发期各项形态指标的影响。主成分分析法结果表明,发芽势、发芽率、最长根长、第一片叶长及胚芽鞘长在PCA下载荷量最大;根据SOM聚类分析结果,‘德抗961’等4个小麦品种属于高度耐盐品种,‘济麦22’等14个小麦品种属于耐盐性品种,‘济麦20’等16个品种属于中等耐盐性品种,‘鲁麦21’等6个小麦品种属于盐敏感性品种。发芽势、发芽率、最长根长、第一片叶长、胚芽鞘长能够作为萌发期小麦耐盐性筛选的主要评价指标,并且结合主成分、SOM聚类分析方法进行小麦萌发期耐盐性鉴定更为科学、方便。     

苗后除草剂喷施时期对杂草防治及冬油菜产量和品质的影响

为了探究苗后除草剂不同施用时期对北方冬油菜田间杂草的防控效果及其对冬油菜生长、产量和品质的影响,以当地主栽甘蓝型冬油菜天油2266和白菜型冬油菜天油H614为试验材料,选用对冬油菜安全的苗后除草剂高效氟吡甲禾灵,设置4个喷施时期处理,于2018-2019年开展大田试验。结果表明,越冬后不同时期喷施苗后除草剂,甘蓝型冬油菜田间杂草总数较对照减少57.54%~92.56%,杂草总鲜重较对照降低75.40%~97.48%,第2时期（3月25日）处理产量较对照增加354.50kg/hm²;白菜型冬油菜田间杂草株防效和鲜重防效分别为55.91%~92.02%和37.17%~97.46%,产量较对照增加2.29%~16.77%。因此,在冬油菜大量返青但未封行前施用苗后除草剂,可显著防控田间杂草并增加冬油菜籽粒产量。     

芫花萜药膜中止早,中孕412例效果分析

芫花萜膜终止早中孕４１２例临床观察的结果表明，对孕１２～１６周的流产成功率为９０．８％，给药至排胎平均时间为２３．４６±１０．３２小时，产时、产后失血平均分别为７１．８７±３３．５６ｍｌ和４５．１７±２０．５８ｍｌ。整个流产过程宫缩缓和，极少强直性宫缩，节律良好，痛苦少，类似正常分娩过程，可作为终止１２～１６周妊娠可供选择的一种有效方法。     

苗期夜温对番茄畸形果发生的影响

试验表明番茄苗期低夜温不仅提高了畸形果发生率，而且也提高了畸形果平均级数和综合指数，并增加了畸形果的类型，同时乱形果在畸形果中所占的比例也增大。试验还认为：引起番茄畸形果大量发生的界限温度在大于６℃和小于１２℃的范围内，低温所需时间为幼苗２片子叶充分展开后１０～１６天，幼苗低温敏感期为２～４片真叶展开期。因此，番茄育苗期间应避免２～４片真叶展开期夜温低于１２℃。