几种环境因子对嘉兰块茎生长和秋水仙碱含量的影响

占自然光42％光强,每天日照9～11小时的处理,对嘉兰干物质积累和秋水仙碱含量的提高比较有利,单株的块茎产量和秋水仙碱的含量也较高;用1～3 ppmGA浸种,对后期块茎产量和秋水仙碱含量均有不同程度的提高;嘉兰地上部茎、叶和块茎的生长具有较强的相关性,如在生长前期利用水、肥促进茎、叶生长,对后期块茎的生长和秋水仙碱含量的增加有利。     

嘉兰光合特性和秋水仙碱含量变化的研究

 嘉兰整个生长期光合速率变化呈一单峰曲线。高峰期前,用促进茎、叶生长和延长有效光合作用时间的方法,能在生长后期提高块茎的产量和秋水仙碱的含量。栽培条件下嘉兰的秋水仙碱含量高于野生条件下生长的。嘉兰的光补偿点在1,000Lx, 光饱和点在35,000Lx。嘉兰的光合作用变化呈双峰曲线,并表现出“午睡”现象。     

嘉兰光合特性和秋水仙碱含量变化的研究

嘉兰整个生长期光合速率变化呈一单峰曲线。高峰期前,用促进茎、叶生长和延长有效光合作用时间的方法,能在生长后期提高块茎的产量和秋水仙碱的含量。栽培条件下嘉兰的秋水仙碱含量高于野生条件下生长的。嘉兰的补偿点在１,０００Ｌｘ,光饱和点在３５,０００Ｌｘ。嘉兰的光合作用日变化呈双峰曲线,并表现出“午睡”现象。     

莲胚发育与核酸,蛋白质含量的变化

莲胚发育达到最大鲜重(开花后21d)前,胚轴和子叶的DNA,RNA都持续增长。开花13d后,蛋白、淀粉等贮藏物质显著积累,核酸增长速度加快。成熟胚轴的DNA和RNA含量很高,而子叶中积累大量的淀粉、可溶性糖和蛋白质。发育前期胚乳的生长速度较快,开花后16d左右鲜重和物质积累达到高峰。胚生长后期胚乳逐渐败育,贮藏物质和结构物质都减少,膨大的子叶逐步取代了胚乳的地位。 莲胚生物大分子物质含量的模式属于双子叶植物类型。讨论了莲胚细胞多倍化的问题。     

菜豆果荚生长与成熟期间糖类及ABA含量的动态变化

淀粉种子成熟期间,可溶性糖不断转化为不溶性糖,同时种子中的内源激素也在发生变化.例如,小麦在开花到成熟期间,籽粒内CTK、GA、IAA含量高峰顺序出现之后,也就是在籽粒成熟后期,ABA含量出现高峰,此时,鲜重也达最大值,随后进入腊熟期。表明籽粒生长的停止与ABA含量高峰的出现有关。菜豆也是淀粉性种子.菜豆果荚在生长与成熟期的糖类转化和淀粉积累是否也与     

茉莉酮酸类物质与块茎形成

一般认为，马铃薯块茎的形成受两种以上的激素调控。赤霉素是促进伸长生长的激素，它对块茎形成起抑制作用。由于块茎只有在短日照条件下才能分化形成，而此时叶片中的赤霉素活性下降，因此，块茎形成的必要条件是赤霉素含量降低。此外，还发现在块茎形成过程中细胞分裂素的含量急剧增加；在马铃薯地下匍匐枝的无菌培养试验中，细胞分裂素可诱导块茎形成；ABA含量在块茎形成完成时达到高峰，它可防止块茎二次生长，使之进入休眠期。Gresory认为在短日照下的马铃薯叶中含有块茎形成物质（tuberinducingsumstance，TIS），由于它向地下部迁…     

嘉兰及其人工栽培

嘉兰(ＧｌｏｒｉｏｓｘｓａｐｅｒｂａＬ.)百合科蔓生草本植物,原产非洲和亚热带地区。我国云南西双版纳海拔1200ｍ以下有野生零星分布。嘉兰喜高温湿润气候,怕寒。一般生长在平坝或河边,阴湿的砂质地及灌木丛中。嘉兰的药用部分为块茎、种子、种壳,主要成份为秋水仙碱,功...     

宁夏不同地区不同品种马铃薯中龙葵素在不同生长期的积累含量测定

采用高效液相色谱-紫外检测器法,分别对宁夏不同地区、不同品种、在覆膜和露地两种生长方式下马铃薯中龙葵素含量进行测定,随着生长时间的延长,在马铃薯的三个生长时期(块茎增长期、淀粉积累和成熟收获期)龙葵素含量逐渐降低,且覆膜马铃薯中龙葵素含量普遍高于露地马铃薯。在块茎增长期,覆膜陇薯14号的龙葵素含量为3.358 mg/100g,均高于其他品种,露地陇薯14号在三个生长时期龙葵素含量均低于其他品种,且成熟收获期龙葵素含量最低。中薯20号在覆膜和露地的条件下,均在成熟收获期有较低的龙葵素含量,可以作为在头营和彭阳地区的主要种植品种。     

氮素对马铃薯品种东农311产量及品质的影响

为了找出马铃薯的合理施氮量,从而为马铃薯产量的提高及品质的改良提供合理依据,本试验通过探讨不同施氮水平对马铃薯的影响,以中晚熟品种东农311为试验材料,在同一磷钾水平条件下,设定6个氮肥梯度,测定马铃薯在各氮肥梯度下,块茎形成后不同时期的干物质积累量及块茎成熟后的产量、品质性状。研究结果表明,在增加氮肥施用量后,随块茎的生长,干物质积累量显著提升;块茎成熟后,淀粉和维生素C的含量随施氮量的增加呈降低趋势,而还原糖和粗蛋白的含量呈升高趋势。并且本试验确定的东农311的最适施氮量为176 kg/hm2。     

不同日照长度下菊芋块茎形成过程中植物激素和同工酶的变化

每日8～13小时日照可以诱导菊芋(Helianthus tuberosus)开花和块茎的形成,每日14小时以上的日照则抑制其开花和块茎的形成。生长在短日照(每日8小时日照)和自然日照下的菊芋,在花芽刚一出现时匍匐茎即开始膨大,CTK含量也随之增加,块茎膨大最快时,CTK含量最高。生长在长日照(每日18小时日照)下的菊芋,匍匐茎始终不膨大,其中CTK含量一直保持较低水乎。诱导前菊芋匍匐茎中含有一定数量的GA,短日照诱导25天后的第5天,GA含量减少,低水平的GA一直维持到最后。在长日照下生长30天后的匍匐茎GA含量增长1倍多,GA含量一直维持较高水平。自然日照下匍匐茎膨大前GA含量变化不大,膨大开始后则显著减少。在短日照诱导中喷施GA_3溶液,匍匐茎膨大也被抑制。在短日照稻自然日照下菊芋块茎形成过程中,过氧化物酶同工酶的强度和酶带数随匍匐茎的膨大而增大,生长在长日照下的菊芋,匍匐茎不膨大,过氧化物酶同工酶也变化不大。     

Starch Synthesis in Developing Potato Tubers

The activities of enzymes involved in starch metabolism were measured at intervals during tuberization and the early stages of tuber growth in Solanum tubersum grown in water culture under controlled environmental conditions. Starch synthase, ADPglucose pyrophosphorylase, UDPglucose pyrophosphorylase and phosphorylase activities all increased during tuber development, the most pronounced increases occurring in the activities of ADP-glucose pyrophosphorylase and phosphorylase. The activity ratio ADPglucose pyrophosphorylase/phosphorylase was lowest in slow growing tubers and hightest in fast growing tubers. In addition, high sugar concentrations in fast growing tubers and low sugar concentrations in slow growing tubers suggested that enzyme levels might be influenced by sugar concentration. The activities of starch synthase, phosphorylase and ADPglucose pyrophosphorylase were increased 2–2.5 fold by the presence of 100 mM K⁺. It is concluded that the major enzyme changes occur as a consequence of tuber initiation and that starch accumulation is controlled, at least in part, by the activities of ADPglucose pyrophosphorylase and phosphorylase.     

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.     

大血藤叶片生化成分的动态变化

对自然条件下大血藤叶片生化成分的动态变化进行了研究。结果表明;大血藤叶片可溶性糖,淀粉和总糖含量的动态变化有相同的趋势。在叶片生长季节早期含量较低。随着叶片的生长发育,其含量逐渐上升。至8月达到最大值后逐渐下降,叶片总糖含量与日均净光合速率的季节变化呈极显著的正相关,在整个生长季节中,可溶性糖含量比淀粉高,大血藤叶片总蛋白含量季节性变化呈单峰曲线,在展叶初期含量较低;随后迅速上升,至8月达到最大值后逐渐下降,叶片总糖含量与日均净光合速率的季节变化呈极显著的正相关。在整个生长季节中,可溶性糖含量比淀粉高。大血藤叶片总蛋白含量季节性变化呈单峰曲线,在展叶初期含量较低;随后迅速上升,在6月初达到最大值后逐渐下降,落叶前降至最低占,可溶性蛋白质含量的季节性变化曲线与总蛋白含量基本相似,DNA含量在叶生长初期大幅度上升,至6月达到高峰后迅速下降,以后基本趋向稳定,RNA在叶生长初期有所上升,峰值也出现在6月,以后缓慢下降,到9月降至最低值,在落叶前又有所回升,总核酸含量的季节变化与RNA变化相似,RNA/DNA比值在生长季节中出现3次高峰,大血藤叶片总黄酮含量季节性变化呈“双峰”型,第1高峰期在开花期的5月。第2高峰期在秋季的9月份。     

番茄果实成熟过程中钙调素含量变化及其与乙烯生成的关系

应用酶联免疫吸附法(ELISA)测定番茄(Lycopersicon esculentum Mill大红品种)果实成熟过程中钙调素(CaM)含量的变化。果实开始成熟(发白期),CaM含量随着呼吸跃变上升,成熟时(粉红期)达到最大,过熟衰老时则下降。果实内部乙烯浓度、ACC含量及其合成酶活性也随跃变而增加,随过熟衰老而降低。GaM含量在果实不同部位中的分布有明显差异,跃变上升期以子房腔组织含量最高,并由中心向外逐渐降低,外周果皮含量最低。此时用外源乙烯催熟处理促进各部位CaM增加。成熟衰老时子房腔组织首先衰老,CaM含量大为降低,但在中柱和果皮中却高于跃变上升期。外源乙烯促进衰老使CaM下降。Ca~(2+)促进番茄圆片CaM含量增高和乙烯产生,CaM抑制剂CPZ,TFP在降低CaM含量的同时也抑制乙烯的产生。     

Effect of gibberellic acid on growth and carbohydrate metabolism of developing tubers of potato (Solanum tuberosum)

Potato plants (Solanum tuberosum L. cv. Ostara) were grown in aerated water culture in a controlled environment. When the tubers had reached a diameter of 1–3 cm. ¹⁴C-labelled or unlabelled gibberellic acid (GA₃) was applied to the surface of the stolons at points approximately 1 crn from the developing tubers, and treatment continued for 10 days. - Significant quantities of GA₃ moved into tuber tissue within 2–4 days of hormone application. This influx of GA₃ was accompanied by a marked reduction in both the activity of ADPG-pyrophospharylase and the ratio ADPG-pyrophosphorylase/starch phosphorylase and an increase in the activity of UDPG-pyrophosphorylase. Starch phosphorylase activity initially increased slightly but then fell, whereas the activity of starch synthase remained constant throughout the experiment. The soluble sugar composition of the tubers changed qualitatively towards a pattern characteristic of growing stolon tips prior to tuber initiation, but there was no clear evidence of net starch degradation. Changes in the activities of the enzymes were observed prior to noticeable effects of the hormone on tuber growth rate or the development of new stolons at the tuber eyes. - GA₃- treated tubers imported more ¹⁴C from labelled photosynthate than expected on the basis of growth rate. However, the capacity to convert solub#e-¹⁴C to ethaTiol-insoluble-¹⁴C (predominantly starch) was reduced in comparison with non-treated tubers. - The observed changes in carbohydrate composition and enzyme activities indicate that GA₃ induces a drastic change in potato tuber metabolism towards a pattern characteristic for the termination of the storage process.     

山药异淀粉酶基因克隆及其在淀粉代谢中的作用北大核心CSCD

为了明确异淀粉酶基因(ISA 3)在山药淀粉代谢中的作用,该研究以‘毕克齐’和‘大和长芋’山药为试验材料,测定了块茎中淀粉及组分含量和异淀粉酶活性等;采用RT-PCR技术克隆了ISA 3,并进行生物学分析及山药块茎不同膨大期和不同组织间ISA 3基因的表达等。结果表明:(1)山药‘大和长芋’的直链淀粉、支链淀粉和总淀粉含量均显著高于‘毕克齐’,且两品种的淀粉含量随生长发育的变化均呈先升高后降低的趋势,并均于种植后120 d时达到最高,但‘毕克齐’的异淀粉酶(ISA)活性在整个膨大期均高于‘大和长芋’。(2)成功克隆获得山药ISA 3开放阅读框长1584 bp,编码527个氨基酸;ISA3为亲水性蛋白。(3)不同品种块茎在膨大时期的ISA 3基因表达趋势不同,‘毕克齐’中呈先显著上调随后下调,而在‘大和长芋’中表达总体下调,且在山药的叶、茎和块茎中均有表达,存在明显的组织特异性。(4)ISA活性与山药淀粉及支链淀粉含量呈显著和极显著正相关关系,但ISA活性与ISA 3的表达量呈负相关关系。研究表明,异淀粉酶参与了山药块茎中淀粉的合成,且主要对支链淀粉的合成起关键作用,ISA 3基因的表达可能对异淀粉酶活性和淀粉的合成起负调控作用。     

3种薯蓣属植物珠芽糖类含量变化与茎叶生长的关系

以山药、日本薯蓣和黄独3种薯蓣属植物为材料,研究珠芽育苗中其茎叶生长与珠芽内的干物质、淀粉、可溶性糖、还原糖含量和淀粉酶活性变化的关系.结果表明: 3种薯蓣在茎蔓生长过程中珠芽内的干物质和淀粉含量均逐渐降低.山药和黄独的珠芽可溶性糖含量在茎蔓生长初期不断增加,随着茎蔓节数继续增加又逐渐降低,而还原糖含量在叶片展开前不断增加,叶片展开后又急剧降低;日本薯蓣珠芽的可溶性糖和还原性糖含量随着茎蔓节数增加逐渐上升,但保持相对较低水平.3种薯蓣珠芽内α-淀粉酶活性均强于β-淀粉酶,其在茎蔓和叶片生长中发挥重要作用.研究发现,薯蓣珠芽内淀粉主要在α-淀粉酶作用下转化分解为还原糖和可溶性糖,从而为茎蔓和叶片生长提供能量,且还原糖含量与叶片生长的关系更为密切.     

纳米硒对紫色马铃薯生长及其矿质元素含量和品质特性的影响

以紫色马铃薯品种‘黑美人’为试材,采用水培法,分别用不同浓度(0、0.38、0.19和0.095 mmol/L)纳米硒溶液对紫色马铃薯进行叶面喷施处理,研究纳米硒对紫色马铃薯生长、矿质元素含量及品质特性的影响。结果表明:(1)与对照相比,各硒处理马铃薯的生物量与单株结薯数均显著增加,其中喷施0.095 mmol/L硒处理的生物量最高且增幅达1.5倍,喷施0.19 mmol/L硒处理的单株结薯数显著增加2.2倍。(2)纳米硒能够显著提高紫色马铃薯叶片、根系、块茎硒含量,各器官硒含量大小呈现:根系>叶片>块茎的特点,且喷施0.095 mmol/L硒处理块茎总硒含量达0.106 mg/kg,较对照显著提高0.65倍,达到了马铃薯块茎的富硒标准;同时纳米硒可在不同程度上调控K、Ca、Mg、Mn、Zn在马铃薯各器官中的分配。(3)随施硒浓度的增加,紫色马铃薯块茎中淀粉、可溶性蛋白及游离氨基酸含量呈先增加后降低的变化趋势,均在喷施0.19 mmol/L硒处理下达到最大值,且较对照分别显著增加56.33%、26.91%和27.89%;块茎中花青素、可溶性糖含量呈下降趋势,均在喷施0.095 mmol/L硒处理下达到最大值,且较对照分别显著提高24.73%、25.33%;而块茎中硝态氮含量呈上升趋势,在喷施0.095 mmol/L硒处理下最低并较对照显著降低34.82%。研究表明,叶面喷施0.095~0.19 mmol/L纳米硒溶液能够显著促进紫色马铃薯生长和单株结薯数,提高硒元素含量,调控矿质元素含量在器官中分配,有效改善其块茎品质特性。     

Gonadal development and steroid hormone profile of wild caught grey mullet (Mugil cephalus)

The grey mullet Mugil cephalus is one of the popular and fast growing fishes being cultured in tropical and subtropical regions. In the present study, histological observation of gonadal development and corresponding changes in sex steroid levels from different maturity stages of wild caught male and female were studied. In female, testosterone and 17β-estradiol increased with the advancement of maturation and reached peak (17β-estradiol, 323 ± 13 pg/ml; testosterone, 938 ± 7.87 pg/ml) in mature stage, whereas the level of progesterone was maximum (488 ± 4.9 pg/ml) during ripe stage. Vitellogenin level in serum showed a similar trend as 17β-estradiol. In case of male, the testosterone level in serum increased gradually with advancement of maturation and was maximum (1820 ± 40.25 pg/ml) during ripe stage, whereas significant decrease in 17β-estradiol and progesterone was noticed with advancement of maturation. The fundamental information from this investigation would be useful for developing protocol for accelerating maturation and spawning under captive condition.     

Decreased sucrose content triggers starch breakdown and respiration in stored potato tubers (Solanum tuberosum)

To change the hexose-to-sucrose ratio within phloem cells, yeast-derived cytosolic invertase was expressed in transgenic potato (Solanum tuberosum cv. Desirée) plants under control of the rolC promoter. Vascular tissue specific expression of the transgene was verified by histochemical detection of invertase activity in tuber cross-sections. Vegetative growth and tuber yield of transgenic plants was unaltered as compared to wild-type plants. However, the sprout growth of stored tubers was much delayed, indicating impaired phloem-transport of sucrose towards the developing bud. Biochemical analysis of growing tubers revealed that, in contrast to sucrose levels, which rapidly declined in growing invertase-expressing tubers, hexose and starch levels remained unchanged as compared to wild-type controls. During storage, sucrose and starch content declined in wild-type tubers, whereas glucose and fructose levels remained unchanged. A similar response was found in transgenic tubers with the exception that starch degradation was accelerated and fructose levels increased slightly. Furthermore, changes in carbohydrate metabolism were accompanied by an elevated level of phosphorylated intermediates, and a stimulated rate of respiration. Considering that sucrose breakdown was restricted to phloem cells it is concluded that, in response to phloem-associated sucrose depletion or hexose elevation, starch degradation and respiration is triggered in parenchyma cells. To study further whether elevated hexose and/or hexose-phosphates or decreased sucrose levels are responsible for the metabolic changes observed, sucrose content was decreased by tuber-specific expression of a bacterial sucrose isomerase. Sucrose isomerase catalyses the reversible conversion of sucrose into palatinose, which is not further metabolizable by plant cells. Tubers harvested from these plants were found to accumulate high levels of palatinose at the expense of sucrose. In addition, starch content decreased slightly, while hexose levels remained unaltered, compared with the wild-type controls. Similar to low sucrose-containing invertase tubers, respiration and starch breakdown were found to be accelerated during storage in palatinose-accumulating potato tubers. In contrast to invertase transgenics, however, no accumulation of phosphorylated intermediates was observed. Therefore, it is concluded that sucrose depletion rather than increased hexose metabolism triggers reserve mobilization and respiration in stored potato tubers.