基因型和环境对以色列野生二棱大麦籽粒营养品质的影响

为探讨基因型和生长环境对野生二棱大麦营养性状的影响,对源自以色列不同地区的9个群体60个基因型野生二棱大麦材料在3个环境条件下的籽粒可溶性蛋白质、氨基酸、植酸、无机磷和淀粉含量及粒重进行测定,并对检测数据进行了单因素方差分析(One-Way ANOVA)、相关性网络分析(correlation-based network analysis,CNA)和斯皮尔曼秩相关分析(Spearmanp’s Rho Correlation)。结果表明,野生二棱大麦各被测性状与生长地土壤成分存在显著相关性(P0.01);以色列野生二棱大麦籽粒中无机磷、总淀粉含量和粒重受生长环境和基因型的共同影响,而植酸、可溶性蛋白质、氨基酸含量等性状则主要受生长地环境的影响。     

An economically based evaluation index for perennial and short‐term ryegrasses in New Zealand dairy farm systems

Grazed pastures based on ryegrass species provide most of the feed for dairy cattle in New Zealand. There are many cultivars of perennial (Lolium perenne), annual and Italian (L. multiflorum), and hybrid (L. boucheanum) ryegrasses available for dairy farmers to use in pasture renewal. This study describes an index which ranks ryegrass cultivars relative to a genetic base according to the estimated economic value (EV) of seasonal dry matter (DM) traits. A farm system model was used to derive EVs (Grazed pastures based on ryegrass species provide most of the feed for dairy cattle in New Zealand. There are many cultivars of perennial (Lolium perenne), annual and Italian (L. multiflorum), and hybrid (L. boucheanum) ryegrasses available for dairy farmers to use in pasture renewal. This study describes an index which ranks ryegrass cultivars relative to a genetic base according to the estimated economic value (EV) of seasonal dry matter (DM) traits. A farm system model was used to derive EVs ($ ha^?1 calculated as change in operating profit divided by unit change of the trait) for additional DM produced in different seasons of the year in four regions. The EV of early spring DM was consistently high across all regions, whereas EV for late spring DM was moderate to low. Genotype × environment analysis revealed significant reranking of DM yield among ryegrass cultivars across regions. Hence, separate performance values (PVs) were calculated for two mega‐environments and then combined with the corresponding season and region EV to calculate the overall EV for twenty‐three perennial ryegrass and fifteen short‐term ryegrass cultivars. The difference in operating profit between the highest ranked and lowest ranked perennial ryegrass cultivar ranged from $556 ha^?1 to $863 ha^?1 year^?1 depending on region. For short‐term ryegrasses used for winter feed, the corresponding range was $394 to $478 ha^?1 year^?1. Using PV for DM yield, it was estimated that plant improvement in perennial ryegrass has added $12–$18 ha^?1 year^?1 (depending on region) operating profit on dairy farms since the mid‐1960s.     

干旱胁迫下‘宁玉’草莓生长发育及相关基因表达特点

为分析基因诊断草莓在干旱逆境条件下生长状态的可行性,以‘宁玉’草莓为试材,调查了不同干旱胁迫条件下的生长特点以及与生长素合成、脱落酸合成、花果发育、色素合成相关的10个基因的表达情况。研究结果表明:在不同干旱条件下草莓均可完成从营养生长到生殖生长的生命周期,所选基因也都行使并完成了其调控功能。与对照植株相比,在轻度和中度干旱胁迫(50%~65%土壤持水量)条件下,草莓植株的物候期较对照(80%土壤持水量)提早,而在严重干旱胁迫(35%土壤含水量时)条件下延缓,随着干旱胁迫条件的加重,草莓植株、叶片、果实明显变小,果实着色加深。每个基因在不同干旱条件下表达水平的变化趋势基本一致,且都与相应的物候期以及生长发育时间长短的变化情况相一致,但所选基因在几种干旱条件下其表达开始的早晚、表达水平的高低以及表达相应程度持续时间的长短存在不同。在轻度和中度干旱条件下,这些基因的表达时间提早,但持续时间较短,表达水平高于对照;而在重度干旱条件下,这些基因的表达开始的时间较对照延缓,表达水平较低但持续时间拉长。上述研究结果表明,利用基因的表达信息可以提前推断草莓植株在不同干旱条件下的生长发育状态,了解干旱胁迫对草莓生长发育的影响以及为是否需要提早采取管理措施等提供重要依据。     

水、旱条件下小麦苗期部分农艺性状的遗传分析

为研究水分胁迫对小麦幼苗部分农艺性状的影响,分析这些性状与干旱胁迫的关系。以‘青麦6号’和‘烟农24’杂交形成的F2:3群体为材料,采用主基因+多基因混合遗传模型对其进行遗传分析。水、旱2种条件下,根长和根鲜重均为1对加性-显性效应主基因模型;茎鲜重、茎干重、根干重、根茎鲜重比和根茎干重比的最适遗传模型不同。干旱胁迫条件下,茎鲜重主基因遗传率为37%,茎干重、根长、根鲜重、根干重、根茎鲜重比及根茎干重比主基因遗传率分别是51%、81%、74%、56%、50%、68%。茎鲜重、茎干重、根干重等性状,尽管检测到主基因,但在水旱条件下遗传模型不同,可进一步研究其遗传规律。     

绿豆种质资源农艺性状的因子分析及综合评价

为合理利用绿豆种质资源,本研究以55份绿豆种质资源为材料,通过对其10个农艺性状进行因子分析及聚类分析。结果表明:10个农艺性状的变异系数为8.57%~47.19%,其中单株粒重变异系数最大,生育期变异系数最小。将10个农艺性状简化为结荚数因子、高度因子、粒数因子、粒重因子和生育期因子5个独立的主因子,该5个主因子可以反映原始信息的86.340%。经综合得分排序,评选出10份性状优良的绿豆种质资源。聚类分析将55份种质资源的10个数量性状分为3大类,类群I、类群II、类群III分别包括22份、7份、26份材料。结合综合评价和聚类分析认为,在黑龙江绿豆生产中,‘安绿8号’、‘佳木斯黄绿豆’、‘冀绿1号’可作为品种选育的改良亲本,也可大面积种植利用。     

棉花陆海染色体片段代换系BC_7F_2群体纤维产量和品质性状表现及相关分析

为了揭示棉花染色体片段代换系BC_7F_2纤维产量性状和品质性状之间的相关关系,筛选纤维品质优异的新材料。以1套陆海染色体片断代换系为材料,对BC7F2高代回交群体的产量性状与纤维品质性状的表性数据进行评价及偏相关分析。结果表明:群体各性状的平均值接近于轮回亲本‘中棉所36’,群体内存在丰富的遗传变异。纤维上半部平均长度超轮回亲本比例为30.25%,断裂比强度超轮回亲本比例为71.25%,衣分超轮回亲本比例为29.38%。总体上单铃重与马克隆值、整齐度指数呈极显著正相关,衣分与上半部平均长度、断裂比强度呈显著负相关,与单铃重呈极显著负相关。从中筛选出部分纤维品质突出的单株,纤维上半部平均长度高于30.00 mm,断裂比强度高于31.00 cN/tex。     

Comparative performance of the highly invasive Mimosa invisa and its less invasive subspecies under different nutrient and light conditions

Invasive plants may be more plastic than non‐invasive plants and maintain high fitness under various environmental conditions. Previous studies mainly focused on the comparisons between invasive and native plants, and comparisons between highly invasive and less invasive exotic species are still relatively rare, especially for comparisons at the subspecies level. This study examined the effects of nutrient addition and shading on the performance of the highly invasive Mimosa invisa and its less invasive subspecies M. invisa var. inermis under either isolated or competitive conditions. Nutrient addition increased biomass and plant height and decreased root‐to‐shoot ratio (R/S). Shading decreased biomass and R/S and increased plant height. Under isolated conditions, the two invaders did not differ in R/S, plant height and plasticity of these traits in response to nutrient addition or shading, and the two invaders also did not differ in biomass production under each of the nutrient and light treatments. When the two invaders competed with each other, M. invisa outcompeted M. invisa var. inermis under high soil nutrient conditions, and the two invaders did not differ in performance under other growth conditions. Thus, only considering competition may we find out the difference between highly invasive species and their closely related, less invasive subspecies. Management of M. invisa should focus on habitats with high soil nutrient availability, in which M. invisa is more likely to dominate.     

外源ABA对苹果砧木叶片解剖结构 及内源激素含量的影响

通过光镜和透射电镜分别观察外源脱落酸（ABA）处理下楸子（Malus prunifolia）、平邑甜茶（M. hupehensis）和新疆野苹果（M. sieversii）叶片解剖结构及叶绿体超微结构的变化,利用扫描电镜和酶联免疫法分别研究ABA处理对叶片气孔特征及其内源激素含量的影响。结果表明：与对照相比,ABA处理下楸子、平邑甜茶和新疆野苹果的叶厚分别减少了7.93%、0.25%和0.81%,栅栏组织厚度分别减少了31.43%、8.53%和4.99%（P＜0.05）,海绵组织厚度分别增加了10.34%、6.14%和5.63%（P＜0.05）,叶肉组织结构疏松度（SR）分别增加了19.59%、6.55%和6.50%。ABA处理下楸子和平邑甜茶的栅栏组织/海绵组织厚度比值（P/S）及叶肉组织结构紧密度（CTR）较对照显著减少（P＜0.05）,其中,P/S值分别下降37.86%和13.82%,CTR分别下降25.46%和8.29%,而新疆野苹果的P/S值和CTR下降但不显著。此外,ABA处理下楸子和平邑甜茶的上表皮细胞厚度较对照分别增加了5.82%和6.43%,新疆野苹果的较对照减少了26.23%（P＜0.05）;楸子和新疆野苹果的下表皮细胞厚度较对照增加了12.09%和14.21%（P＜0.05）,平邑甜茶的较对照减少了12.56%。平邑甜茶和新疆野苹果叶片上下角质层厚度较对照显著增加（P＜0.05）,而楸子的变化不显著。在ABA诱导下,3种砧木的气孔密度、气孔大小（长度×宽度）及其开口度和开张比均不同程度地下降,其中,楸子的较对照分别下降了3.62%、7.12%×19.59%、67.60%和86.66%,平邑甜茶的分别下降了3.50%、4.99%×20.65%、32.42%和58.24%,新疆野苹果的分别下降了8.54%、0.92%×12.06%、20.37%和16.35%。ABA处理下3种砧木叶片细胞中叶绿体的数量变少,类囊体结构排列疏松,叶绿体上的淀粉粒趋于变小。外施ABA使3种砧木叶片内源ABA和玉米素核苷（ZR）的含量极显著增加（P＜0.01）,其中楸子ABA和ZR含量比对照分别增加30.83%和13.31%,平邑甜茶的分别增加62.40%和45.28%,而新疆野苹果的分别增加了37.07%和17.06%。楸子和新疆野苹果叶片的吲哚乙酸（IAA）和赤霉素（GA）含量无显著变化,而平邑甜茶叶片的IAA及GA含量比对照分别增加了62.62%和20.62%（P＜0.01）。总之,在ABA处理下,3种苹果砧木的叶片组织解剖结构和气孔特征都发生旱生性结构变化,叶肉细胞中淀粉粒趋于变小,叶片内源ABA和ZR水平增加显著,而IAA和GA水平变化因基因型不同而存在差异。     

不同生育期水分胁迫对玉米农艺性状的影响

为了研究不同生育期玉米水分胁迫对玉米农艺性状的影响,为干旱、半干旱地区玉米抗旱提供理论依据。以玉米在苗期、拔节期、抽雄-吐丝、灌浆-成熟期进行水分胁迫,测量玉米株高、穗位高、叶面积、穗部性状,对比充分灌水与非充分灌溉下玉米农艺性状差异。利用Jensen模型求解出玉米各生育期水分敏感系数,验证水分胁迫对玉米产量的影响。结果表明在拔节期进行干旱处理的株高、穗位高、叶面积受影响较大,有明显的抑制作用。抽雄—吐丝期干旱胁迫对穗部性状的形成较为明显,并且对产量影响较大。