宁麦9号与扬麦158株高及其构成因素的遗传解析

宁麦9号与扬麦158是我国长江中下游麦区的主栽品种和骨干亲本,长江中下游麦区近3年来审定品种中80%都是其衍生后代,研究其性状的遗传具重要意义。以宁麦9号与扬麦158为亲本构建的包含282个家系的重组自交系群体为材料,利用Illumina 90k芯片对群体进行基因型分析,建立高密度遗传图谱。连续3个生长季对株高及节间长度、穗长等株高构成因素进行测定,结合遗传图谱对株高及相关性状进行QTL定位,获得14个控制株高及其构成因素的稳定表达位点。通过进一步位置比对,聚焦到6个染色体区段,初步明确了各节间对株高的遗传调控机制。同时,将6个染色体区段中同源性较低的连锁标记转化为适用于高通量筛选的KASP标记,利用101份区域试验材料进行标记效应验证,结果显示聚合Qph-2D与Qph-5A.1两个位点具有较高的选择效率,继续聚合Q2A后,中选材料显著减少,可能降低选择效率;对Q2A与Q5A两个一因多效位点的选择建议以降低株高的等位变异为主;Qd1-5D可作为穗下节间(D1)的选择标记对株高展开优化选择。期望以上结果能为长江中下游麦区的小麦株高遗传改良提供帮助。     

3种植物生长调节剂对坛紫菜自由丝状体生长与光合色素含量的影响

采用单因素分析法,比较研究了添加3种外源植物生长调节剂(吲哚乙酸IAA、2,4-二氯苯氧乙酸2,4-D、激动素KT)对野生型坛紫菜(Pyropia haitanensis)自由丝状体生长及光合色素含量的影响。结果表明:与对照组相比,低浓度的IAA(0.5~4.0 mg·L~(-1))和KT(0.5~2.0 mg·L~(-1))对藻体的特定生长率有显著影响,以2.0 mg·L~(-1)IAA和1.0 mg·L~(-1)KT对藻体的促生长效应最大,培养25 d时藻体鲜重增加最大,分别是对照组的1.90倍和1.52倍(P0.05)。高浓度的IAA(6.0~10.0 mg·L~(-1))和KT(4.0~10.0 mg·L~(-1))却会抑制藻体生长(P0.05)。培养25 d时,与对照组相比,2.0 mg·L~(-1)IAA和1.0 mg·L~(-1)KT均有利于叶绿素a(Chl a)和类胡萝卜素(Car)的合成,Chl a含量分别增加了23.7%和23.8%;Car含量分别增加了31.0%和28.6%(P0.05)。然而,高浓度的IAA和KT(6.0、10.0 mg·L~(-1))不利于Chl a的合成,其处理浓度越高,Chl a含量下降越多。与对照组相比,较低浓度的IAA(1.0~2.0 mg·L~(-1))明显促进藻红蛋白(PE)和藻蓝蛋白(PC)合成,其中2.0 mg·L~(-1)IAA处理组PE、PC含量最高,分别增加了59.1%和45.7%(P0.05)。较低浓度的KT(0.5~2.0 mg·L~(-1))均有利于PE、PC合成,其中0.5 mg·L~(-1)KT处理组的PE、PC含量增加最多,分别提高了48.4%和50.5%(P0.05)。高浓度的IAA(6.0、10.0 mg·L~(-1))和KT(10.0 mg·L~(-1))则明显降低了PE、PC合成(P0.05)。2,4-D对藻体的特定生长率和光合色素合成无显著影响(P0.05)。     

A compendium of raw material digestibilities for barramundi,Lates calcarifer

A series of experiments were conducted to examine the nutrient and energy digestibility of a suite of diets and specific test raw materials when fed to juvenile (179 to 439 g) barramundi, Lates calcarifer. Each of the diets was prepared using a twin‐screw extruder to mimic modern aquafeed manufacturing processes. Each of the diets was fed to juvenile barramundi for a minimum of a week to allow acclimation to the diet before the faeces were collected using stripping methods. A broad range of digestible nutrient and energy values among the different raw materials were observed, with protein digestibilities ranging from 36% to 106% and energy digestibilities ranging from 36% to 93%. This range in nutritional values of the different raw materials provides substantial utility in allowing the formulation of diets on a digestible nutrient and energy basis across the Asia Pacific region. These results also provide critical data to help underpin the replacement of both fishmeal and fish oil in barramundi diets.     

茶氨酸合成酶基因的SNP挖掘和遗传定位

茶氨酸合成酶(Theanine synthetase,TS)基因是茶树茶氨酸代谢过程中的关键酶基因。本研究以氨基酸含量差异明显的亲本及其杂交所得F_1子代为研究材料,克隆TS基因的c DNA序列,挖掘其SNPs位点,并成功将杂合SNP位点定位在遗传连锁群上。研究结果显示,通过序列比对在亲本间检测到3个SNPs,验证得到1个杂合的位点SNP735。将此位点成功转化为dCAPS标记,该标记在子代中的基因型分离比为1∶1,利用该群体已构建的茶树遗传图谱进行遗传定位,将dCAPS标记定位在连锁群LG03上,相邻标记为TM299和TM517。联合此标记及其相邻标记与游离氨基酸总含量和茶氨酸含量进行统计分析,表明具有显著的相关性。     

Allometric Estimates of Aboveground Biomass Using Cover and Height Are Improved by Increasing Specificity of Plant Functional Groups in Eastern Australian Rangelands

Plant aboveground biomass (AGB) is a useful metric to assess ecosystem functioning, and its sensitivity to changing environmental conditions provides insight into potential global change impacts. Allometric estimates of AGB using vegetation characteristics such as plant cover or height provide nondestructive biomass proxies for repeated measurements but can introduce uncertainty to estimates. We estimated the relationship between both plant cover and a cover·height index and AGB for 15 plant species from six sites to identify the most reliable approach to estimate biomass nondestructively in semiarid eastern Australian rangelands. Estimates were made by grouping species at four different levels of specificity, to test whether generic estimates were more robust than grouping species based on life history and morphological characteristics. Estimates were then tested on a 1.5-m² plot at each site for validation. In all cases, models were highly significant (P < 0.001) with adjusted R² values ranging from 0.42 to 0.96 for cover models and 0.38 to 0.98 for cover·height index models. We found the addition of height improved model fits in four groups while reducing model fits in two groups. The error around AGB estimates for cover·height index−based models ranged from −66.8 to 4% (absolute mean 35%). Cover-based models had errors between −13.4% and 53% (absolute mean 14.2%). For cover-based estimates of AGB in validation plots, grouping plants by plant functional types (PFTs) increased accuracy (absolute mean error 17.3%) compared with estimates using data from all 15 species (absolute mean of 65.2%). Overall cover was a useful surrogate to estimate AGB (with the exception of one site, accuracy ranged from −2.3% to 11.5%), while height (thought to be a surrogate for canopy characteristics) provided benefit in a few circumstances. We suggest that future research should test additional nondestructive proxies and group species based on PFTs to improve AGB estimates using allometry.     

细叶旱芹地上部化感物质粗分离物对4种草坪草及5种牧草的化感作用

采用滤纸培养皿法，以发芽率、发芽势、根长和苗长为指标，研究细叶旱芹（Cyclospermum leptophyllum(Pers.) Sprague ex Britton et P. Wilson）地上部化感物质对4种草坪草和5种牧草受体植物的种子萌发和幼苗生长的影响。结果表明，细叶旱芹地上部化感物质对4种草坪草和5种牧草的种子萌发和幼苗生长均有抑制作用，其中对种子发芽势抑制最明显，抑制率最高达96.3%；其次是对幼苗根长的抑制作用，抑制率最高达91.1%。通过比较种子萌发和幼苗生长的测定指标，得出5种馏分对草坪草的化感作用为石油醚相＞氯仿相＞正丁醇相＞乙酸乙酯相＞水相，而对牧草的化感作用为石油醚相＞乙酸乙酯相＞氯仿相＞正丁醇相＞水相。说明不同受体植物对相同萃取相组分的化感作用强弱存在差异，细叶旱芹地上部化感物质主要存在于石油醚馏分中，可进一步从中分离提取活性物质。     

MYB转录因子参与植物非生物胁迫响应与植物激素应答的研究进展

基因的时空表达受转录因子的精确调控。植物在面对不利环境因素比如高温、低温、干旱、盐碱等胁迫时其细胞生理生化会迅速地从“舒适”状态转变进入“胁迫响应”状态。这种快速响应的状态转变依赖于植物对胁迫信号的感知及传递、激素通路(脱落酸、茉莉酸等)的激发、转录因子的活化等复杂的过程;最终植物通过胁迫相关基因的表达、次生代谢转变、抗氧化物质的积累等实现胁迫条件下细胞内环境的再平衡从而获得生存。植物MYB(v-MYB avian myeloblastosis viral oncogene homolog)转录因子就是上述转变中的重要参与者。本文介绍了植物MYB转录因子的结构特征、分类,综述了近些年来MYB转录因子与非生物胁迫,以及植物激素应答过程相关的研究进展。     

一氧化氮影响植物不定根发生的研究进展

近年来,一氧化氮(NO)作为一种气态信号小分子,在植物中的研究越来越多,尤其是植物NO的产生机理及其在植物不定根发生中的作用机制研究取得了很大突破。本文概括了NO在植物体内的产生途径,详细阐述了NO及其与其他信号分子互作对植物不定根发生的影响,总结了植物不定根发生过程中NO调控的相关基因表达;最后,展望了NO参与植物不定根发生的研究趋势,以期为NO在植物不定根发生的应用研究提供理论参考。     

Effects of fish meal replacement by low‐gossypol cottonseed meal on growth performance,digestive enzyme activity,intestine histology and inflammatory gene expression of silver sillago (Sillago sihama Forsskál) (1775)

A 56‐day feeding trial was conducted to evaluate the effects on the growth performance, digestive enzyme activity, inflammatory genes expression and intestine histology of silver sillago, Sillago sihama (Forsskål 1775), by replacing fish meal (FM) with low‐gossypol cottonseed meal (LCSM). Five isonitrogenous and isolipidic diets were formulated, including R0 group (control, containing 550.0 g/kg FM), R16 group (88.5 g/kg LCSM and 461.5 g/kg FM), R32 group (177.0 g/kg LCSM and 373.0 g/kg FM), R48 group (265.5 g/kg LCSM and 284.5 g/kg FM) and R64 group (354.0 g/kg LCSM and 196.0 g/kg FM). Fish fed R0 and R16 groups had a significantly higher weight gain rate (WGR) and specific growth rate (SGR) than R48 and R64 groups (p < .05). In contrast to whole‐body crude protein, whole‐body moisture increased with the FM level of substitution (p < .05). With the increased amount of LCSM in the diet, the activity of intestinal amylase (AMS) increased significantly (p < .05), and intestinal trypsin (TRP) decreased (p < .05). Dietary LCSM substitution upregulated the expression of intestinal tumour necrosis factor‐α (TNF‐α), the nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB), and interleukin one beta (IL‐1β), but downregulated tight junction proteins ZO‐1(ZO‐1), transforming growth factor beta‐3 (TGF‐β3) and interleukin 10 (IL‐10) expression. Histological analysis revealed progressive morphological damage to the mid‐intestine with higher levels of FM replacement. These results showed that 88.5 g/kg (16%) of FM replaced by LCSM with amino acids (methionine and lysine) supplementation did not significantly reduce growth compared with FM‐based control.     

含刚性沉水植物明渠水流结构的试验研究

【目的】得到含刚性沉水植物明渠的水流结构。【方法】采用粒子图像测速仪(PIV),用有机玻璃棒模拟刚性植物,在不同来水流量、植物密度条件下对明渠水流结构进行了试验研究。【结果】无植物时平均流速沿垂向呈对数分布规律,有植物时则呈现明显的分区分布特性。无植物时紊动强度值沿垂向变化不大,有植物时在植物顶端位置处紊动最剧烈。流量或植物密度越大,植物顶端位置的流速梯度就越大,植物层上方的流速最大值也越大。植物密度越大,植物顶端位置的紊动强度越大,植物密度对水流紊动强度由最大值减小到最小值的区域影响很大。【结论】刚性沉水植物的存在会改变水流结构,增强紊动掺混,增强流体质点交换和能量传递,且上述影响会随着流量或植物密度的增大而增强。