AGPase基因植物表达载体的构建及对烟草的转化

将大肠杆菌BL21的AGPase基因定向连接在受体质粒pCAMBIA2301载体上,从而构建植物表达载体,转化烟草获得了转基因植株。经GUS组织化学染色、PCR、Southern blot以及RT-PCR鉴定证实,该基因已导入烟草基因组中。淀粉含量测定结果显示,转基因植株比非转基因植株淀粉含量平均增加了13.1%,由此验证了该载体构建的成功与可用性,为下一阶段用该载体转化木薯主栽品种提高块根淀粉含量的研究奠定了基础。     

木薯蔗糖合成、转运与块根淀粉积累关系研究

该研究以淀粉含量不同的两个木薯品种(辐选01和华南124)为材料,通过测定各品种不同生育期叶、茎和根的蔗糖含量及块根淀粉含量,分析了蔗糖合成、转运和块根淀粉积累过程的相关性.结果表明:与华南124相比,在整个生育期内辐选01叶、茎的蔗糖含量均较高,块根蔗糖含量在块根膨大初期以前高于华南124,块根膨大初期以后则相反.在木薯的整个生育期,与辐选01相比,华南124的淀粉合成量和淀粉合成速率均较低.叶和茎蔗糖含量的变化规律与淀粉合成速率的变化规律相反,即块根淀粉积累明显加快时叶和茎的蔗糖含量略呈下降趋势,而块根淀粉合成减慢时叶、茎的蔗糖含量又开始上升.随着生育期的延后,块根蔗糖含量越来越低.在块根形成初期,蔗糖含量最高的组织部位为块根,其次为茎秆,最低的是叶片;而在块根成熟期时则相反,即蔗糖含量最高的部位是叶片,其次为茎杆,块根的蔗糖含量最小.相关性分析结果表明,木薯叶片蔗糖含量与块根淀粉含量呈显著的正相关;茎秆蔗糖含量与块根淀粉积累量呈不显著的正相关;块根蔗糖含量与淀粉积累量呈显著的负相关.由此可见,木薯叶、茎和根蔗糖与块根淀粉积累过程密切相关,其中叶片合成蔗糖的能力与块根利用蔗糖的能力在淀粉的积累过程中发挥关键作用.该研究结果为木薯的生产选育与高效栽培提供了理论依据.     

秋水仙碱诱变甜菊多倍体的研究

用０．１％秋水仙碱溶液处理甜菊实生苗生长点,可诱变产生甜菊多倍体（四倍体）植株,用８次点滴处理,诱变率可达３１．２５％。染色体数鉴定表明：四倍体甜菊染色体数是２ｎ＝４４,而二倍体甜菊染色体数是２ｎ＝２２．形态学和解剖学的观察表明,四倍体比二倍体甜菊植株的茎矮壮,叶片增大,长度增长２．１倍,宽度扩大２．３倍,叶片加厚１．７倍,叶色更浓绿,叶片气孔数减少,气孔变大。叶片糖苷含量测定表明：四倍体的叶片含量为１５．７％,而二倍体的叶片含量为１０．８％,前者比二倍体叶片含量提高４．９％。     

国内外栽培木薯(Manihot esculenta Crantz)种质资源表型多样性分析

以国内外不同地理来源的228份木薯资源为材料,通过评价植株15个茎和块根的描述型表型性状及7个与产量相关的数量性状,初步了解其表型遗传多样性,为种质资源创新利用、针对性地引种和育种亲本选配提供理论参考。结果表明,国内外不同地理来源木薯资源描述型性状频率分布较一致,多以张开型、三分叉、30°~45°分枝角度、主茎内皮浅绿色居多,块根性状以表皮粗糙、外皮淡褐色、内皮乳黄色、肉质白色资源居多;数量性状多样性指数为1.895~2.073,描述型性状多样性指数为0.435~1.889,表明228份木薯资源遗传多样性丰富,且数量性状存在较大程度变异(8.91%~44.60%),国内资源块根直径极显著高于国外资源,国外资源干物率极显著高于国内资源,说明国内外资源的块根直径和干物率具有明显的遗传差异,利用现有资源可能选育出产量高、品质好的品种。两步聚类分析将参试资源明显划分为两大类群,类群Ⅰ主要特征为株型张开、分枝角度中等偏大,群体不整齐,主茎较粗,薯块产量较高资源;类群Ⅱ为株型紧凑直立型、分枝角度小,群体整齐,主茎较细,薯块干物率较高资源。在今后的育种工作中,可选择同类资源中表型差异互补的种质为亲本,聚合优良性状,以达到育种期望目标。     

木薯SBEI基因片段克隆及块根特异性反义表达载体的构建

为了抑制木薯支链淀粉的合成,提高直链淀粉含量,改变木薯淀粉结构,培育工业用燃料酒精型木薯品种,本研究利用RT-PCR方法,用木薯块根cDNA克隆获得支链淀粉合成的关键酶基因SBEI的部分片段,对其进行序列分析表明与GenBank序列高度同源,同源性为99.22%;并以pBI121为基础,构建了以块根特异性表达启动子Sporamin驱动的SBEI基因反义结构的植物表达载体.     

氧化钙对水稻幼苗的生理作用研究

利用几种含钙化合物处理土壤后播种水稻,发现氧化钙具有显著的生理活性,土壤中含量在1．0％时明显增加旱育身水稻幼苗高度,增加根数和加快叶片发育速度,进一步研究发现0．5－1．5％CaO能够降低稻苗细胞电解质渗透率和脂质过氧化过程,增加叶绿素含量和体内可溶性蛋白含量,并能提高POD活性,增强稻苗抗低温能力。     

杜仲雌雄株树皮和叶片中氨基酸及其含量的研究

杜仲（ＥｕｃｏｍｍｉａｕｌｍｏｉｄｅｓＯｌｉｖ）是我国特有的雌雄异株植物,具有极高的药用价值、工业价值和观赏价值。主要依靠种子繁殖。为了有计划地进行定性栽培,就需要对幼龄植株进行早期性别鉴定。许多生理指标都可能作为性别鉴定的依据。通过对杜仲中氨基酸含量和组成的分析表明,不同性别植株树皮和叶片中均含有被分析的１７种氨基酸,其中胱氨酸和蛋氨酸在雌雄株间差异明显,雄株树皮和叶片中胱氨酸的含量分别高出雌株７６．９８％和４５．０４％;树皮和叶片中蛋氨酸含量雌株分别高出雄株２０．５０％和１８．７７％。这是否反映了杜仲雌雄的性别差异,值得探讨。必需氨基酸总量在树皮和叶片中均表现为雌株高于雄株,且叶片中必需氨基酸总量高于树皮中的含量。     

钙对镉胁迫下花生生理特性、产量和品质的影响

通过盆栽试验,选用高油品种豫花15和高蛋白品种XB023,研究了不同浓度钙对镉胁迫下不同类型花生品种营养生长、叶片叶绿素含量、光合速率、保护酶活性等生理特性及产量和品质的影响.结果表明： 施钙可以缓解镉胁迫对花生植株主茎高和侧枝长的抑制作用,增加花生植株干物质量,提高叶片叶绿素含量和光合速率,提高叶片超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）活性和可溶性蛋白质含量,降低丙二醛（MDA）的积累量,减轻镉胁迫对花生叶片的伤害;施钙可以缓解镉胁迫对花生的减产作用,增加花生荚果和籽仁产量,其增产的主要原因是增加了单株结荚数和出仁率;施钙可以促使籽仁中可溶性糖向粗脂肪和蛋白质转化,增加籽仁中脂肪和蛋白质含量,改善镉胁迫下花生籽仁品质.施钙可以降低两花生品种籽仁中镉含量,对豫花15的降低效果好于XB023.     

钙对镉胁迫下花生生理特性、产量和品质的影响水

通过盆栽试验,选用高油品种豫花15和高蛋白品种XB023,研究了不同浓度钙对镉胁迫下不同类型花生品种营养生长、叶片叶绿素含量、光合速率、保护酶活性等生理特性及产量和品质的影响.结果表明:施钙可以缓解镉胁迫对花生植株主茎高和侧枝长的抑制作用,增加花生植株干物质量,提高叶片叶绿素含量和光合速率,提高叶片超氧化物歧化酶( SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性和可溶性蛋白质含量,降低丙二醛(MDA)的积累量,减轻镉胁迫对花生叶片的伤害;施钙可以缓解镉胁迫对花生的减产作用,增加花生荚果和籽仁产量,其增产的主要原因是增加了单株结荚数和出仁率;施钙可以促使籽仁中可溶性糖向粗脂肪和蛋白质转化,增加籽仁中脂肪和蛋白质含量,改善镉胁迫下花生籽仁品质.施钙可以降低两花生品种籽仁中镉含量,对豫花15的降低效果好于XB023.     

提高木薯循环培养的次生体胚再生植株频率研究

用木薯成熟体胚子叶作外植体诱导次生体胚,接种7d或15d后分别在诱导培养基或成熟培养基中加入AgNO3,可明显提高植株再生频率。前者可使体胚再生植株频率由对照的40．5％提高到58．1％;后者可使植株再生频率由对照的36．1％提高到61．3％。用ABA进行上述处理,效果更加显著。诱导期处理,可使植株再生频率由对照的40．5％提高到72．6％;成熟期处理,植株再生频率由对照的36．1％提高到81．3％。若诱导7d后,将2,4－D浓度由4．0mgL-1降至2．0mgL-1,并加AgNO3,继续诱导15d,转到附加0．25mgL-1ABA的成熟培养基中培养至30d,能极显著地促进体胚的发育和成熟,使植株再生频率达到一个相当高的水平,最高达95％,平均每个外植体产生的植株数达39．6个,分别相当于对照的2．38倍和2．46倍。     

牛角花齿蓟马为害对苜蓿无性系根茎叶及同化产物分配的影响

为探索同化产物分配利用与苜蓿耐蓟马的关系,本试验以扦插的抗蓟马苜蓿无性系R-1和感蓟马苜蓿无性系 I-1为材料,研究不同虫口牛角花齿蓟马为害对苜蓿的抗性、根、茎和叶生长特性及可溶性糖含量的影响.结果表明: 随着虫口压力的增大,R-1和I-1苜蓿的受害指数升高;在相同虫口压力下,R-1苜蓿的受害指数显著低于I-1.受蓟马为害后,R-1和I-1苜蓿株高降低、叶面积减少、茎秆变细、节间长变短、节间数增加,根颈和主根直径加粗、侧根增多.在低虫口密度下,随虫口压力增大,R-1和I-1苜蓿地上部生物量增加,根冠比下降,分配到茎的生物量比例升高;在高虫口密度下,地上部生物量随虫口压力增大而减少,根冠比增加,分配到根系的生物量比例升高;R-1根冠比和茎生物量比例随虫口压力变化曲线的拐点均为每枝条5头,I-1根冠比和茎生物量比例随虫口压力变化曲线的拐点均为每枝条3头.在低虫口压力下,R-1苜蓿茎和叶中的可溶性糖含量随虫口压力增加而升高;在高虫口压力下,茎和叶中的可溶性糖含量随虫口压力增加而下降;根中可溶性糖含量随虫口压力增加持续下降.I-1根、茎和叶中的可溶性糖含量均随虫口压力增加持续下降.牛角花齿蓟马为害后,R-1根、茎和叶的农艺性状及抗性比I-1好,对同化产物的分配利用率高.     

钾对小麦旗叶蔗糖和籽粒淀粉积累的影响

 利用冬小麦品种‘鲁麦22’(Triticum aestivum cv. `Lumai 22’)在大田条件下研究了钾素对小麦旗叶蔗糖和籽粒淀粉积累及其有关酶活性的影响。结果表明,钾素有利于提高旗叶光合速率,增强开花后旗叶磷酸蔗糖合成酶活性,提高旗叶中蔗糖的含量;从而提高了灌浆期间籽粒中蔗糖的供应,增强了籽粒中蔗糖合成酶和腺苷二磷酸葡萄糖焦磷酸化酶的活性,加速了淀粉积累速率,提高了粒重和产量。     

缺氮和复氮对菘蓝幼苗生长及氮代谢的影响

对基质育苗后水培的菘蓝进行缺氮与复氮处理,分析其生长情况及氮代谢产物含量的变化,探讨缺氮和复氮对菘蓝幼苗生长及氮代谢的影响,以提高菘蓝产量和品质以及栽培过程中的氮素利用效率。结果显示:(1)正常供氮条件下,菘蓝幼苗的叶绿素含量、谷氨酰胺合成酶(GS)活性、硝态氮含量、靛玉红含量为最高,而其株高、主根直径、根的鲜重与干重、叶的鲜重与干重、根系活力均最小。(2)缺氮处理增加了菘蓝幼苗的主根直径和根干重,提高其根系活力和硝酸还原酶(NR)活性,促进游离氨基酸在叶中的积累;但降低了GS的活性,也降低了叶中硝态氮、可溶性蛋白、靛玉红及根中游离氨基酸的含量;缺氮对叶中靛蓝的含量无明显影响。(3)复氮处理增加了菘蓝幼苗的株高、主根长、根鲜重、叶鲜重、叶干重,提高了其根系活力,降低了NR和GS的活性;与对照相比,复氮降低了叶中硝态氮含量,提高了叶中可溶性蛋白、靛蓝及根中游离氨基酸的含量,但对叶中游离氨基酸和靛玉红含量影响较小。研究表明,缺氮后再复氮有利于菘蓝幼苗叶的生长,同时有利于增加其叶内靛蓝含量,从而提高其产量和品质。     

A transgenic study on affecting potato tuber yield by expressing the rice sucrose transporter genes OsSUT5Z and OsSUT2M

In many plants, sucrose transporters are essential for both sucrose exports from sources and imports into sinks, indicating a function in assimilate partitioning. To investigate whether sucrose transporters can improve the yield of starch plant, potato plants (Solanum tuberosum L. cv. Désirée) were transformed with cDNAs of the rice sucrose transporter genes OsSUT5Z and OsSUT2M under the control of a tuber-specific, class-I patatin promoter. Compared to the controls, the average fructose content of OsSUT5Z transgenic tubers significantly increased. However, the content of the sugars and starch in the OsSUT2M transgenic potato tubers showed no obvious difference. Correspondingly, the average tuber yield, average number of tubers per plant and average weight of single tuber showed no significant difference in OsSUT2M transgenic tubers with controls. In the OsSUT5Z transgenic lines, the average tuber yield per plant was 1.9-fold higher than the controls, and the average number of tubers per plant increased by more than 10 tubers on average, whereas the average weight of a single tuber did not increase significantly. These results suggested that the average number of tubers per plant showed more contribution than the average weight of a single tuber to the tuber yield per plant.     

Enhancing the expression of starch synthase class IV results in increased levels of both transitory and long-term storage starch

Starch is an important renewable raw material with an increasing number of applications. Several attempts have been made to obtain plants that produce modified versions of starch or higher starch yield. Most of the approaches designed to increase the levels of starch have focused on the increment of the amount of ADP-glucose or ATP available for starch biosynthesis. In this work, we show that the overexpression of starch synthase class IV (SSIV) increases the levels of starch accumulated in the leaves of Arabidopsis by 30%-40%. In addition, SSIV-overexpressing lines display a higher rate of growth. The increase in starch content as a consequence of enhanced SSIV expression is also observed in long-term storage starch organs such as potato tubers. Overexpression of SSIV in potato leads to increased tuber starch content on a dry weight basis and to increased yield of starch production in terms of tons of starch/hectare. These results identify SSIV as one of the regulatory steps involved in the control of the amount of starch accumulated in plastids.     

链格孢菌粗毒素对菊花‘神马’幼苗生长及生理代谢的影响

由链格孢菌引起的菊花黑斑病严重降低了菊花的品质和产量.链格孢菌在代谢过程中分泌的粗毒素是菊花黑斑病发生的主要致病因子之一.本文从菊花黑斑病发病叶片中分离筛选出致病真菌链格孢菌1株,研究其粗毒素对菊花幼苗‘神马’生长的影响以及测定盆栽幼苗叶片细胞膜相对透性、抗性物质含量、诱导酶活性及代谢物质含量变化.结果表明: 链格孢菌粗毒素对菊花‘神马’幼苗的株高、茎粗、根长均有抑制作用,毒素浓度与抑制效果呈正相关,且粗毒素原液处理14 d后,菊花幼苗株高、茎粗、根长受到显著抑制,分别比对照减少了28.9%、21.4%和23.3%;链格孢菌粗毒素处理菊花‘神马’幼苗后,根系组织细胞膜透性随着毒素浓度的增加而增加,在同一毒素浓度处理下,菊花幼苗叶片细胞膜透性随着处理时间的增加呈先增大后降低的趋势;毒素原液处理菊花幼苗后,菊花幼苗叶片中抗性物质可溶性蛋白、丙二醛(MDA)以及脯氨酸含量均显著提高.链格孢菌10倍稀释液处理对叶片苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)活性的提高最为显著.链格孢菌粗毒素对切花菊‘神马’幼苗的致病作用主要通过抑制菊花幼苗根、茎的正常生长,增加菊花幼苗叶片细胞膜透性,影响切花菊幼苗叶片中抗性物质代谢以及提高叶片保护酶活性而影响植株正常生理代谢.     

干旱胁迫下接种丛枝菌根真菌对七子花非结构性碳水化合物积累及C、N、P化学计量特征的影响

以濒危植物七子花二年生幼苗为研究材料,采用盆栽试验方法,研究干旱胁迫和接种丛枝菌根真菌(AMF)处理对幼苗不同器官C、N、P化学计量关系和非结构性碳水化合物(NSC)含量的影响。试验共设计4个处理:对照(CK)、干旱胁迫(D)、接种AMF(AMF)、干旱胁迫和接种AMF(D+AMF)。结果表明: 在干旱胁迫下七子花根系AMF的侵染率显著下降,但接种AMF处理植株的株高、叶片数显著高于未接种处理。接种AMF显著提高了干旱胁迫下植株根、叶可溶性糖和NSC含量及茎、叶淀粉含量,且茎和叶可溶性糖与淀粉比显著下降。干旱胁迫导致植株C含量在根和叶中显著增加,P含量在茎中显著减少;与干旱胁迫相比,胁迫下接种AMF植株根、茎、叶P含量及叶C含量显著提高,而根C、N含量及茎C含量显著降低。胁迫下接种AMF植株根、茎C∶N、C∶P、N∶P和叶N∶P均显著低于单一胁迫处理。NSC与C∶N∶P计量比的相关性分析表明,根、叶P含量与可溶性糖和NSC含量呈显著正相关,茎P含量与淀粉和NSC含量呈显著正相关,各器官N∶P与NSC含量呈显著负相关。综上,干旱胁迫显著抑制了七子花幼苗的生长,接种AMF通过提高植株根和叶的可溶性糖含量、根的可溶性糖/淀粉,增加地上部分淀粉含量,促进P元素吸收和降低各器官N∶P来增强植株耐旱性,从而提高七子花幼苗在干旱环境中的存活率。     

Growth of the Tops of Sweet Potato and the Translocation of the Nutrients from Leaves

1. Experiments were carried out in Hangchow on the increase of dry matter in the tops of sweet potato plants. The increase can be divided into three periods: (1) slow accumulation of dry matter; (2) rapid increase of accumulation of dry matter, reaching a maximum; (3) decline of accumulation of dry matter, later on account of senility and the dropping of leaves, there was a marked reduction in the dry matter of the tops. The increase in dry matter is in proportion to the leaf area. The amount of fertilizer used is closely related to the increase of dry matter and leaf area. 2. The yield of sweet potato is related to the increase in dry matter of the tops of the plant. To a certain extent, the greater the amount of dry matter, the more rapidly will the tubers enlarge, finally results in a higher yield. Excessive use of fertilizer leads to an abnormal elongation of the plant. During this period an increase in dry matter of the tops not only fails to induce the enlargement of the tubers, but also leads to the consumption of the dry matter, and consequently causes a reduction in yield of sweet potato. From the curve of T/R ratio, the sooner the downward translocation of the tops nutrients occurs, the faster the tubers will form and enlarge. 3. Experiments with p32 show that the various growth conditions of the tops are closely correlated with the translocation of the tubers. With well growing and high yielding plants the nutrients move from the tops to the tubers as soon as the root enlarges. This translocation is even accelerated during the later stage. During the earlier stage of development, much of the plant nutrition is translocated to the stems and leaves, particularly to the latter; then gradually it is diverted to the leaves and the root system, and finally concentrates in the roots. The increase of the area of green leaves and the number of branches during the period of early growth, and the promoting of favourable conditions for the formation and enlargement of the roots, as well as the facilitating of the translocation of nutrients to the roots during the later stage are the determinative factors necessary for obtaining high yield of sweet potato.     

The Influence of Removing Tubers on Dry-matter Production and Net Assimilation Rate of Potato Plants

To study the effect of removing tubers on growth and net assimilationrate (E) of potato, plants were grown in pots partly filledwith soil with the shoot growing through a polythene cover.Tubers developed in the space between the cover and the soilsurface. Removing tubers immediately they began to form had little effecton E at the beginning of the experiment but later greatly reducedit. Shading reduced E more at the beginning of the experimentthan later. Removing tubers decreased total dry weight, butmuch of the material that would have moved to tubers accumulatedin leaves and stems. In intact plants the loss of weight byshading was mainly from the tubers; in plants without tubersit was mainly from stems and leaves. Removing tubers increasedleaves on lateral stems. Increasing the amount of nitrogen supplieddiminished the effect on E of removing tubers, presumably becausethe extra allowed other sinks for carbohydrate to develop. Thegrowth of some buds of the potato plant is so strongly inhibitedthat they cannot grow and act as sinks for excess carbohydratewhen tubers are removed. Such internal inhibition of growthmay sometimes suffice to influence the magnitude of E of normalplants. Removing tubers usually increased sugar and starch contentand protein N content of stems and leaves.     

盐胁迫对裸果木幼苗生长和叶片相关生理指标的影响

裸果木起源于古地中海,为亚洲中部荒漠区分布的第三纪孑遗植物种,对研究旱生植物演化过程具有重要的科学价值。以一年生裸果木(Gymnocarpos przewalskii)实生苗为材料,在盆栽条件下用质量浓度为0.4%、0.8%、1.2%和1.6%的NaCl溶液进行盐胁迫处理,测定各NaCl处理下裸果木幼苗叶片的抗氧化酶活性、渗透调节物质含量、叶绿素含量、相对电导率(REC)、丙二醛(MDA)含量以及株高、基径,根、茎、叶、总干重,根冠比变化,探讨裸果木幼苗对盐胁迫的生理耐受性。结果显示,(1)随着盐胁迫程度的加重,裸果木幼苗株高、基径,以及根、茎、叶干重和总干重整体呈下降趋势,而根冠比呈上升趋势;裸果木幼苗株高、基径和根干重在0.4%NaCl处理下较对照变化不显著,但其茎干重、叶干重和总干重在各NaCl处理下均显著低于对照。(2)随着盐胁迫程度的加重,裸果木幼苗叶片的可溶性糖(SS)含量、可溶性蛋白(SP)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性均先升高后降低,而脯氨酸(Pro)含量、过氧化氢酶(CAT)活性、REC、MDA含量均呈持续升高趋势;在0.8%NaCl处理...