水稻半外卷叶突变体sol1的表型分析与基因定位

适度卷曲有利于提高水稻叶片的光合效率,增加植株光合产物的有效积累量。我们利用甲基磺酸乙酯(EMS)处理籼型水稻保持系西农1B,获得一个稳定遗传的水稻半外卷叶突变体。该突变体从十叶期开始各叶片逐渐向外卷曲直至半卷状,并伴随茎秆半矮化和叶片披垂,暂被命名为semi-outcurved leaf 1(sol1)。与野生型(WT)相比,sol1的叶片卷曲指数均达到30%以上(P<0.01);倒一、倒二、倒三、倒四节节间长度和穗长极显著缩短,倒一、倒二、倒三叶的叶夹角显著或极显著增加;有效穗数、千粒重、每穗实粒数、结实率显著或极显著下降,一次枝梗数则增加11.3%(P<0.05)。sol1的蒸腾速率、胞间CO2浓度、气孔导度显著高于野生型。石蜡切片显示,sol1倒一叶的泡状细胞体积变小,数量显著增多,表皮细胞体积略微增大。遗传分析表明,sol1的半外卷叶性状受1对隐性核基因调控,定位于6号染色体标记JY6-3和JY6-10之间165 kb的物理范围内,共含15个注释基因。qRT-PCR结果表明,与泡状细胞相关的内卷基因和外卷叶基因RL14、Roc5、REL1在突变体sol1中呈不同程度的上调,NRL、BRD1、OsHox32、ADL1、LC2则呈不同程度的下调。研究结果为SOL1基因的克隆和功能研究奠定了基础。     

有机生态栽培基质配比对生菜生长及品质的影响

以传统基质草炭、蛭石及腐熟羊粪和玉米秸秆为原料,配制成12种不同配比的栽培基质,以商品叶菜类栽培基质作为对照,研究不同基质配方对生菜生长的影响,以期获得最适合生菜栽培的基质配比组合。结果表明,不同组合基质配比均能满足生菜的正常生长,所有处理的株高、叶面积、单株鲜重和单株干重都较对照组(CK)有着不同程度提高,其中T11(草炭∶腐熟羊粪∶玉米秸秆∶蛭石=1∶4∶3∶4)条件下各指标表现最好,分别较CK提高了31.80%、47.15%、59.43%和79.53%;从生理生化指标来看,T11处理的Vc含量最高,是CK的2.5倍;T10(草炭∶腐熟羊粪∶玉米秸秆∶蛭石=3∶1∶4∶4)的根系活力是所有处理中最高的,达到CK的2.02倍;T12(草炭∶腐熟羊粪∶玉米秸秆∶蛭石=3∶4∶1∶4)处理的叶绿素含量最高,是CK的1.41倍,硝酸盐含量最低,较CK降幅达到74.59%。通过隶属函数进行综合比较分析,我们认为T11是所有供试处理中最适合生菜栽培的基质配比。     

彝族高寒山区芜菁抑菌作用及黄酮含量的初步研究

用标准曲线法分析了芜菁Brassica rapa L.制作品——干板菜提取物对食物腐败菌的抑菌作用；用薄层层析、紫外吸收光谱等方法定性测验了干板菜提取物物质；以芦丁作对照品,用标准曲线法、单因素实验、正交试验等研究了乙醇提取千板菜总黄酮的最佳条件,并测定了总黄酮含量.研究表明:干板菜水提物对大肠杆菌具有较好的抑制作用；干板菜乙醇提取物除金色葡萄球菌外,对参试的大肠杆菌、巨大芽孢杆菌、毛霉等9种常见食物腐败菌均具有抑制作用,尤其对大肠杆菌和巨大芽孢杆菌具有良好的抑制作用.用乙醇提取干板菜中总黄酮的最佳条件为:乙醇浓度为70％,提取时间为3h,料液比为1∶50,提取温度为70℃.干板菜样品中总黄酮含量不低子12.69 mg/g,远高于常见蔬菜.     

加拿大一枝黄花入侵机理及控制策略

从遗传特征、繁殖特征、生理生态特点、环境的可入侵性、人类活动干扰、化感作用、与土壤微生物的作用7个方面介绍了加拿大一枝黄花的入侵机理,并提出了机械防治、化学防治、生物防治等控制策略.     

两个新的黄瓜SnRK2基因的鉴定及特征分析

植物SnRK2基因在非生物逆境应答中具有重要功能,但有关黄瓜SnRK2基因的研究尚缺乏报道。笔者通过对黄瓜基因组的重新挖掘,发现了2个新的SnRK2基因,分别与拟南芥的SnRK2.4和SnRK2.10同源。本试验对2个新的黄瓜SnRK2基因的结构特征及顺式调控元件进行了全面分析,为进一步研究其在黄瓜逆境应答中的功能奠定了基础。     

早熟禾新品种农菁15的选育

为选育高产优质饲用和坪用草品种,将早熟禾优异风干种子经50Gy60 Co-γ射线辐射处理后,通过田间系统选择,结合生物产量、返青率、营养品质、抗病性及坪用性能等指标的检测,选育出农菁15早熟禾;该品种抗寒、耐盐碱、抗病性强、适应性广、饲用价值较高;与对照优异相比,具有青绿期长、草产量高、种子产量高等优点;在黑龙江高寒地区平均干草产量达3 832.6kg·hm-2,成熟期平均种子产量达510.2kg·hm-2;适宜在黑龙江全省推广种植。     

苦瓜对8种蔬菜的化感作用

以8种海南主要栽培的蔬菜为受体,采用室内生测法研究苦瓜(Momordica charantiaL.)茎叶水浸提液对其化感作用。结果表明:苦瓜茎叶水浸提液对8种受体植物的种子萌发和幼苗生长均有一定的化感效应,且化感作用方式和强度在受体间及指标间存在显著差异;化感作用综合效应的平均值大小顺序为:辣椒黄瓜豇豆菜豆萝卜樱桃番茄胡萝卜番茄。试验结果为建立合理的栽培制度提供了理论和试验依据。     

Association analysis for detecting significant single nucleotide polymorphisms for phosphorus-deficiency tolerance at the seedling stage in soybean [Glycine max (L) Merr.]

Tolerance to low-phosphorus soil is a desirable trait in soybean cultivars. Previous quantitative trait locus (QTL) studies for phosphorus-deficiency tolerance were mainly derived from bi-parental segregating populations and few reports from natural population. The objective of this study was to detect QTLs that regulate phosphorus-deficiency tolerance in soybean using association mapping approach. Phosphorus-deficiency tolerance was evaluated according to five traits (plant shoot height, shoot dry weight, phosphorus concentration, phosphorus acquisition efficiency and use efficiency) comprising a conditional phenotype at the seedling stage. Association mapping of the conditional phenotype detected 19 SNPs including 13 SNPs that were significantly associated with the five traits across two years. A novel cluster of SNPs, including three SNPs that consistently showed significant effects over two years, that associated with more than one trait was detected on chromosome 3. All favorable alleles, which were determined based on the mean of conditional phenotypic values of each trait over the two years, could be pyramided into one cultivar through parental cross combination. The best three cross combinations were predicted with the aim of simultaneously improving phosphorus acquisition efficiency and use efficiency. These results will provide a thorough understanding of the genetic basis of phosphorus deficiency tolerance in soybean.     

水稻粒宽突变体gw87的基因定位及候选基因分析

【目的】对水稻粒宽突变体gw87（grain width 87）进行表型鉴定、遗传分析、基因定位及候选基因分析,为探明该基因调控水稻籽粒大小的分子机制及应用潜力奠定基础。【方法】利用甲基磺酸乙酯诱变籼稻恢复系材料676R,获得一份籽粒宽度和千粒重显著增加的突变体gw87。对该突变体进行表型观察、农艺性状调查及外源油菜素内酯（BL）敏感性、叶绿素含量、光合参数测定,了解其表型特征及生理特性。调查gw87与676R杂交F₁的表型和F₂群体的分离情况,分析其遗传行为;选取该群体中的突变植株进行高通量测序,并利用gw87与粳稻品种日本晴杂交的F₂代作为定位群体,通过MutMap分析和分子标记定位,遴选候选基因并进行DNA和cDNA测序验证。利用qRT-PCR分析gw87和676R中BR合成途径基因OsDWARF4、D11和D2的表达差异。【结果】与野生型亲本676R相比,gw87突变体的株高降低,节间缩短,其中,倒一节间长度缩短最大,并呈现出扭曲的形态;叶片长度减少,宽度增加;单株有效穗数、主穗穗长和结实率显著降低,但籽粒宽度和千粒重显著增大。BL敏感性试验显示,gw87突变体幼苗对外源BL的敏感性降低。光合色素和光合参数测定表明,gw87光合色素含量增加,光合速率也有所增加。遗传分析表明gw87的突变性状是由1对隐性核基因控制。MutMap分析显示gw87突变基因位于第5染色体中部,在该染色体区域仅有1个碱基突变引起编码氨基酸变化;分子标记连锁分析表明该突变基因位于InDel标记X2和X3之间约101 kb的染色体区域;综合这两方面分析结果,最后遴选出gw87候选基因是编码一个含有AP2/EREBP DNA绑定结构域的转录因子基因LOC_Os05g32270。对该候选基因进行DNA和cDNA测序验证,发现gw87突变体中该基因DNA的第1 041位的碱基由G突变为A,导致与该位点相邻的76 bp内含子序列被剪接为外显子,引起阅读框移码,蛋白翻译提前终止。qRT-PCR分析显示gw87突变体中BR合成途径基因的表达量显著上调,表明gw87突变体中BR信号减弱。【结论】gw87是smos1、shb、rla1、ngr5的新等位突变体,但与这些突变体表型不同,gw87籽粒的宽度和千粒重显著增加,可能是LOC_Os05g32270的突变位点不同,导致其编码蛋白的功能活性不同所造成。     

Acquired Thermo‐Tolerance and Trans‐Generational Heat Stress Response at Flowering in Rice

In rice, pre‐exposure to sublethal treatment followed by harsh lethal treatment is known to improve tolerance of different abiotic stresses at the vegetative stage within and across generations. Our major aim was to test the phenomenon of thermo‐tolerance at flowering across (trans)‐generations and within generation using rice cultivars contrasting for heat stress tolerance at flowering. To test trans‐generational response, plants were exposed to higher temperature at flowering stage and seeds obtained from previous generations were exposed to heat stress during flowering, which recorded significantly lower fertility when exposed to the same degree of stress in their subsequent generations. A pre‐acclimation to moderately high acclimating temperatures imposed over three different durations during the vegetative and initial reproductive stage showed positive response in the tolerant N22, particularly under severe heat stress (40 °C). This finding indicates the possibility of acquiring ameliorative thermo‐tolerant mechanisms at anthesis, restricted to tolerant genetic backgrounds to combat subsequent harsh conditions within the same generation. However, trans‐generational memory was ineffective in mitigating spikelet sterility losses in both tolerant and susceptible backgrounds. Rice is extremely sensitive to heat stress during flowering; hence, similar exercise across other crops of interest needs to be carried out before generalizing conclusions.