高粱种质资源对黑束病的抗性鉴定与评价

2016-2017年,在人工接种条件下对110份高粱种质资源进行了抗黑束病鉴定与评价研究,拟探明高粱抗病性及不同寄主来源的高粱、玉米黑束病菌致病力差异。110份高粱种质资源中,对高粱来源的黑束病菌(GHS-1)表现免疫(IM)的13份(占11.8%),高抗(HR)的17份(占15.5%),抗病(R)和中抗(MR)的各14份(占25.4%);感病(S)的17份(占15.5%),高感(HS)的35份(占31.8%);对玉米来源的黑束病菌(YHS-1)表现免疫(IM)的21份(占19.1%),高抗(HR)的11份(占10.0%),抗病(R)的15份(占13.6%),中抗(MR)的12份(占10.9%);感病(S)的21份(占19.1%),高感(HS)的30份(占27.3%)。上述结果表明,目前高粱育种中广泛应用的育种种质恢复系中抗黑束病材料较为丰富,且不同寄主来源的高粱和玉米黑束病菌致病力存在差异。     

空间诱变高粱突变体的研究

1996年经4返回式卫星搭载处理的纯系高粱品种晋粮5号（CK）的种子经次年播种生,区得少量秆早熟突变体（SP3）。此后连续二年播种,该突变体矮秆早熟性状稳定,该突变体与未经搭载的对照相比多400粒。（3）SP3平均千粒重为34g,对照为27g。（4）SP3叶片变窄,变短,增厚,叶面积减少了43％－22％。（5）SP3穗轴长度比对照增加30％,各节间长度比对照缩短了67％－15％。（6）SP3种子中亮氨酸含量比对照增加15％,可溶性糖含量比对照增加25％,单宁含量降低了30％。     

高粱遗传转化研究进展

高粱是世界上仅次于小麦、水稻、玉米和大豆的重要作物之一,然而由于其高效、稳定的遗传转化体系的建立较难,限制了其转基因研究进程.近年来,随着转基因技术的不断发展和完善,高粱转基因研究也取得了飞速的发展.从高粱遗传转化再生系统中外植体的选择、转化方法、影响转化和基因表达效率的因素等几方面进行了综述,并总结转基因高粱研究进展.     

Embryological Study on Apomixis in a Sorghum Line SSA-1

The Developmental process of apomictic embryo sac and embryo in a sorghum (Sorghum bicolor (L.) Moench. ) line SSA-1 was observed under light microscope, using the method of conventional paraffin sectioning. The result showed that the apomictic development conforms apospory and diplospory. The uninucleate embryo sac underwent mitotic divisions for three times to form a seven-celled or eight-nuclei mature embryo sac including an egg, two synergids, two polar nuclei and three antipodals. The antipodals divided and multiplicated to form an antipodal mass. Moreover, aposporous multiarchesporial cells and multiple embryo sacs were infrequently observed. Without pollination, the egg divided autonomously to form a typical graminaceous mature embryo. The authors counted the apomictic sections in the whole sections and the result showed that the frequency of apomixis was 42%, indicating the facultative apomictic property in the line SSA-1. The characteristics of apomictic process in the line SSA-1 is also discussed.     

Epidermal conductance, stomatal density and stomatal size among genotypes of Sorghum bicolor (L.) Moench

Abstract. The ability of a plant to survive severe water deficits depends on its ability to restrict water loss through the leaf epidermis after stomata attain minimum aperture. At this stage, the rate of water loss is regulated by the epidermal conductance (g_c). Low g_c would be a useful selection criterion to identify genotypes with enhanced survival capability. Consequently, variation in g_c among Sorghum bicolor (L.) Moench genotypes was evaluated. Since there is little conclusive evidence linking g _c with leaf waxiness, alternative hypotheses relating g _c to stomatal trails were also examined. Epidermal conductance varied from 6.3 to 17.6mmol m⁻² s⁻¹ among sorghum genotypes. It was unrelated to stomatal pore length which varied with genotype and to pore depth which was similar for all genotypes measured. However, g _c, increased with increasing stomatal density. This indicates that stomatal density plays a direct role in water loss even at very low conductances. The association of low stomatal density with low g _c is consistent with the hypothesis that at the smallest stomata aperture, water loss from the epidermis above guard cell teichodes becomes a significant source of leaf water loss. Since low g _c is directly related to crop survival under severe water deficits, it is recommended that genotypes with low g _c. be selected using the selection criterion of stomatal density.     

玉米胚发育过程中热激蛋白的合成

35S-Met标记玉米胚蛋白合成结果表明,热激处理(42℃)与对照(25℃)的蛋白合成趋势相近,热激抑制16 DAP的蛋白合成,增加22和34 DAP蛋白合成.SDS-PAGE自显影图谱表明,热激诱导16DAP的胚合成86.4、80.0、73.2 kD等3种分子量较高的热激蛋白,22DAP后热激诱导合成86.4、80.0、73.2、24.4、18.2、16.8和13.6 kD等7种分子量的热激蛋白.2D-PAGE自显影图谱进一步显示,热激诱导22和28 DAP的胚合成近20种热激蛋白,其中超过10种为小分子热激蛋白.特异热激蛋白BiP(HsP70)、PDI(HsP60)Western blot表明,这2种热激蛋白在玉米胚发育过程均有高水平的表达,热激对其合成影响不明显.     

基于荧光SSR标记的玉米自交系遗传结构解析

利用多重SSR-PCR荧光标记检测技术,对本单位自育和引进的259份玉米自交系进行遗传多样性和亲缘关系分析,并以11个归属于不同杂种优势群的代表自交系为参照进行群体结构分析。结果显示,50对SSR引物共检测到214个等位基因变异,基因多态性指数的平均值为0.50,每个SSR标记的多态性信息量(PIC)平均值为0.44。用UPGMA方法将270份自交系划分成3大类群,进一步进行数值化杂种优势群分析,以明确所用种质资源的杂优类群利用方向,为玉米自交系的有效利用和品种的选育提供依据。     

高梁基因组学研究的新进展

高梁是全球第五大禾谷类作物,在干旱、半干旱地区农业生产中占有权其重要的位置。高梁基因组相对较小(750Mbp),遗传多样性丰富,被认为是禾谷类作物比较基因组学研究的模式基因组之一。近年来,综合运用AFLP等分子标记、BAC文库、EST及cDNA作图和FIsH技术,加速了高梁高分辨率基因组图谱的构建。高梁基因测序、基因功能鉴定和克隆,以及遗传转化,亦取得了长足的进展。高梁特有的多种适应逆境胁迫等优异基因资源的发掘及其在作物改良中的应用前景广阔。     

烯效唑浸种对玉米幼苗生长和内源激素含量的影响

烯效唑浸种对玉米苗期叶片和叶鞘伸长生长有抑制作用,且抑制效应随烯效唑浓度的增大而增强,但植株粗壮,叶宽和茎基宽增加,根系增多,根长增加.烯效唑浸种的玉米幼苗中LAA和GA3含量下降,叶鞘中尤为明显;ZT含量则是地上部提高,根中下降,ABA含量提高,植株各器官中(IAA GA3)/ABA比值均下降,IAA/GA3比值均升高,IAA/ZT和GA3/ZT比值则是地上部降低,根中升高.     

纬度对甜高粱营养生长和籽粒产量的影响

为了解甜高粱〔Sorghumbicolor(L.)Moench〕各品种在我国的适应性,在不同地区进行了‘意达利’、‘雷伊’、‘凯勒’、‘M81E’的品种比较试验,对各品种的生育期、株高、茎秆直径、茎秆重量、茎秆汁锤度、籽粒产量与纬度的关系进行了一元线性回归分析。结果表明:纬度变化,实际上是日照长度的变化,对甜高粱营养生长有影响,高纬度有利于其营养生长。各品种对纬度变化反应敏感程度从大到小为:‘意达利’>‘M81E’>‘凯勒’>‘雷伊’。纬度变化对甜高粱籽粒产量也有影响,4个品种的敏感程度从大到小为:‘意大利’>‘M81E’>‘凯勒’>‘雷伊’,4个品种的生育期、茎秆含糖量(汁锤度)、籽粒产量也随着纬度的增高而增加     

PCR Amplification，Cloning and Sequencing of RbcL Coding Region in Mesophyll Cell and Bundle Sheath Cell of Sorghum（Sorghum bicolor L．）

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Cadmium Accumulation by Jack-Bean and Sorghum in Hydroponic Culture

Among the technologies used to recuperate cadmium (Cd) contaminated soils, phytoextraction are particularly important, where the selection of suitable plants is critical to the success of the soil remediation. Thus, the objectives of this study were to evaluate the responses of jack-bean and sorghum to Cd supply and to quantify Cd accumulation by these species grown in hydroponic culture. The plants were subjected to 0, 15, 30, or 60 μmol Cd L^?1 in the nutrient solution, and gas exchange, plant growth and Cd accumulation were measured at 25 days after starting Cd treatments. The Cd supply severely reduced growth of shoots and roots in both species. In jack-bean, Cd decreased photosynthesis by 56–86%, stomatal conductance by 59–85% and transpiration by 48–80%. The concentrations and amounts of Cd accumulated in the plant tissues were proportional to the metal supply in the nutrient solution. Sorghum was more tolerant than jack-bean to Cd toxicity, but the latter showed a greater metal concentration and accumulation in the shoot. Therefore, jack-bean would be more suitable than sorghum for use in Cd phytoremediation programs based on phytoextraction.     

Comparative analysis of callus formation and regeneration on cultured immature maize embryos of the inbred lines A188 and A632

Induction, maintenance, differentiation and embryogenic capacity of callus obtained from immature embryos by culture on induction medium, proliferation medium, maturation medium and regeneration medium, respectively, were compared for two inbred lines of maize, i.e. A188 and A632. The callus of inbred line A188 was embryogenic and maintained embryogenic capacity for at least 1 year. Immature embryos of inbred line A632 formed callus that was not embryogenic. It only produced roots. When sucrose was replaced by sorbitol to induce or improve embryogenesis, again only A188 formed embryogenic callus. Subculture of this callus, however, allowed 4 week intervals in stead of 2 week intervals without loss of embryogenic capacity. When A188 was pollinated with A632 pollen, embryogenic callus was obtained from cultured immature "F₁" embryos, showing that embryogenic capacity was inherited, maternally. The callus did not differ from the embryogenic callus generated on selfed A188 embryos. When A632 was pollinated with A188 pollen, embryogenic callus was obtained too, showing that embryogenic capacity was also inherited paternally, though the embryogenic capacity diminished quickly, and the stability of the callus was lower than in the reciprocal cross. This revised version was published online in June 2006 with corrections to the Cover Date.     

Molecular mapping of the rf1 gene for pollen fertility restoration in sorghum (Sorghum bicolor L.)

We report the molecular mapping of a gene for pollen fertility in A1 (milo) type cytoplasm of sorghum using AFLP and SSR marker analysis. DNA from an F₂ population comprised of 84 individuals was screened with AFLP genetic markers to detect polymorphic DNAs linked to fertility restoration. Fifteen AFLP markers were linked to fertility restoration from the initial screening with 49 unique AFLP primer combinations (+3/+3 selective bases). As many of these AFLP markers had been previously mapped to a high-density genetic map of sorghum, the target gene (rf1) could be mapped to linkage group H. Confirmation of the map location of rf1 was obtained by demonstrating that additional linkage group-H markers (SSR, STS, AFLP) were linked to fertility restoration. The closest marker, AFLP Xtxa2582, mapped within 2.4 cM of the target loci while two SSRs, Xtxp18 and Xtxp250, flanked the rf1 locus at 12 cM and 10.8 cM, respectively. The availability of molecular markers will facilitate the selection of pollen fertility restoration in sorghum inbred-line development and provide the foundation for map-based gene isolation. Received: 22 August 2000 / Accepted: 18 October 2000     

Starch Mobilization in Ultradried Seed of Maize （Zea mays L.） During Germination

The effects of ultradry storage on the starch mobilization in maize (Zea mays L.) seed after aging were investigated. The results indicated that there were no significant differences in the content of ATP, starch, and soluble sugar, as well as the activity of amylase, between ultradried seeds and seeds stored at -20℃ during germination. These results were consistent with the higher level of vigor of the ultradried seed. Sieve tube introduction of a fluorescence dye (carboxyl fluoresceindiacetate) and laser confocal microscopy were used to study the development of plasmodesmata in the ultradried seeds. The results indicated that plasmodesmata developed well in ultradried seeds. Fluorescence analysis also showed that the fluorescence intensity in the radicle of ultradried seeds was stronger than that in seeds with a higher moisture content. This suggests that ultradry treatment has no adverse effects on the seeds. After seed imbibition, cell orgaelles could be resumed. It is concluded that ultradry seed storage is beneficial for maintaining seed vigor and that starchy mobilization proceeds regularly during germination.     

Interactive effects of methyl jasmonate and salicylic acid on floret opening in spikelets of Sorghum

Floret opening of excised spikelets in Sorghum bicolor (L.) Moench and Sorghum Sudanesis (Piper) Stapf was significantly stimulated by immersing into 2 mM methyl jasmonate (MeJA) solution. In male sterile (MS) lines of Sorghum bicolor (L.) Moench, floret opening was more sensitive to MeJA than that in maintainer (MT) lines. Salicylic acid (SA) could abolish the effect of MeJA on the opening of spikelets. These data indicate that MeJA plays a role in floret opening in sorghum, and that SA interacts with MeJA in regulating of this process.     

Two consensus quantitative trait loci clusters controlling anthesis–silking interval, ear setting and grain yield might be related with drought tolerance in maize

Unravelling the molecular basis of drought tolerance will provide novel opportunities for improving crop yield under water-limited conditions. The present study was conducted to identify quantitative trait loci (QTLs) controlling anthesis–silking interval (ASI), ear setting percentage (ESP) and grain yield (GY). The mapping population included 234 F₂ plants derived from the cross X178 (drought tolerant) × B73 (drought susceptible). The corresponding F_2:3 progenies, along with their parents, were evaluated for the above-mentioned traits under both well-watered and water-stressed field conditions in three different trials carried out in central and southern China. Interval mapping and composite interval mapping identified 45 and 65 QTLs for the investigated traits, respectively. Two QTL clusters influencing ASI and ESP on chromosomes 1 (bin 1.03) and 9 (bins 9.03–9.05) were identified in more than two environments, showing sizeable additive effects and contribution to phenotypic variance; these two QTL clusters influenced GY only in one environment. No significant interaction was detected between the two genomic regions. A comparative analysis of these two QTL clusters with the QTLs controlling maize drought tolerance previously described in three mapping populations confirmed and extended their relevance for marker-assisted breeding to improve maize production under water-limited conditions.     

湖北省玉米地方品种的因子分析

对188份湖北省玉米地方品种的23个性状进行了因子分析,结果前7个公因子对变异的累计贡献率达79.9%。因子分析表明,7个独立的公因子较真实地反映了所支配的23个性状及其相互关系。 Abstract:Factor analysis was performed for 23 traits of 188 local varieties of Maize(Zea mays L.)in Hubei Province.The results indicated that the contributive rate of the first seven factors to total variation of population studied accounts for over 79.9%.Factor analysis showed that the seven independent factors may more truly reflecte the 23 traits and their relationship.