水稻对紫外光B辐射增强的生化适应机制

水稻品种１Ｒ６８和Ｄｕｌａｒ生长在室外条件下,在以自然条件（６．０）,１３．０和１９．１ｋＪｍ＾－１ｄａｙ＾－１（分别模拟臭氧浓度下降２０％和４０％时的ＵＶ－Ｂ强度）的紫外光Ｂ（ＵＶ－Ｂ２８０～３２０ｎｍ）进行二周与四周的辐射处理,研究ＵＶ－Ｂ对水稻叶片内一些生化指标的影响,研究结果表明,ＵＶ－Ｂ辐射增强诱导了二个水稻品种对叶片内吸收ＵＶ的类黄酮化俣物的积累,同时使叶片内多胺的含量明显提高,然而,     

天然芸苔素合剂对甘薯产量的影响

在甘薯分枝期（主蔓长５０ｃｍ,分枝长２０ｃｍ左右）喷施０．１５％天然芸苔素合剂７５００倍液,能加速地上部生长,促进光合源发展,提高早封垄,有利于早结薯、结大薯,结果表明,薯蔓比ｃｋ（喷清水）增产１８５．６ｋｇ／６６７ｍ＾２,增幅为２１．６％;薯块比对照增产８１６．３ｋｇ／６６７ｍ＾２,增幅达６２．７％,薯蔓比为２．０３,比ｃｋ１．５２提高０．５１;大薯比例（〉２５０ｇ）占７１．１％,比ｃｋ高１１．     

杂交水稻施用锌,钼微肥的效应分析

以威优６４为材料进行了杂交水稻施用微肥钼（Ｍｏ）、锌（Ｚｎ）两因素各３水平的田间籽粒产量比较试验。结果是：（１）威优６４对钼酸胺不敏感,各处理间籽粒产量无明显差异;（２）施０．７５ｋｇ／６６７ｍ＾２硫酸锌作基肥,比空白ｃｋ籽粒产量增加８．３９％、比施１．５０ｋｇ／６６７ｍ＾２的Ａ３处理增加５．４６％;（３）０．７５ｋｇ／６６７ｍ＾２,１．５０ｋｇ／６６７ｍ＾２硫酸锌作基肥分别使杂交稻威优６４穗粒数     

大豆大垄窄行密植栽培群体生育动态分析

研究表明,大豆大垄窄行密植栽培较垄三栽培生育斯延３￣７ｄ,株高平均增加３￣５ｃｍ,倒伏加重,开花以后单株干重,叶面积及单株荚粒数下降,但群体干重（１８．０１￣１８９．６０ｇ／ｍ＾２）,叶面积指数（０．０３８￣１．２７０）及荚（２３．７￣１４９．６个／ｍ＾２）粒（除合丰２５号６６．７株／ｍ＾２处理处,增加５１．８￣１６３．６个／ｍ＾２）数增加,增加５１．８￣１６３．６个／ｍ＾２）数增加,进而提高大豆     

玉米氮,磷,钾吸收量与施肥效应分析

在相同土壤条件和施肥量下,对玉米,烤烟进行盆栽对比试验,结果表明：玉米抽雄吐丝期地上部吸收氮,磷,钾量的顺序为Ｎ〉Ｋ〉Ｐ,玉米田间小区施肥试验表明;氮,磷,钾肥对玉米的增产效果为Ｎ〉Ｋ〉Ｐ,与其吸收量大小是一致的;而氮,磷,以的优化配比为中氮中磷高钾处理（Ｎ：Ｐ２Ｏ５：Ｋ２Ｏ＝１．０：０．５：０．８－１．０）,即施Ｎ１５－１６ｋｇ／６６７ｍ＾２,Ｐ２Ｏ５７．５－８．０ｋｇ／６６７ｍ＾２,Ｋ２Ｏ１２     

石大豆1号高产栽培技术研究

采用二次通用旋转设计研究种植密度、尿素、三料过磷酸钙对石大豆１号产量影响，结果表明：这三项农艺措施对石大豆１号产量的影响依次为密度＞三料过磷酸钙＞尿素，适于石 大豆１号高产的密度为１．２９万－１．４５万株／６６６．７ｍ＾２、尿素为８．１－１１．０ｋｇ／６６６．７ｍ＾２、三料过磷酸钙为６．９－１０．７ｋｇ／６６６．７ｍ＾２。     

温凉区小麦套作玉米最佳模式的研究

本试验采用Ｌ１６（４＾５）正交设计,对贵州西部温凉地区分带轮作中影响小麦套作玉米复合产量（值）的主要因子带宽,小麦,玉米及其窝距进行了研究。结果：（１）表现最佳的模式有二个,一是１．５０ｍ带宽＋毕麦１０号＋贵毕３０３＋玉米窝距２０．０ｃｍ,二是１．５０ｍ带宽＋贵丰１号＋贵毕３０１＋窝距２３．３ｃｍ（２）试验最佳模式复合产量达５８８．５４ｋｇ／６６７ｍ＾２,复合产值达７３９。０８元／６６７ｍ＾２,比     

鸭梨不同枝类叶片光合速率在生长期的变化趋势

用改进半叶法测定鸭梨不同部位叶片和不同枝类叶片不同时期的光合速率，结果表明，９年生密植鸭梨外围新梢叶和短枝叶的光合速率分别为１６．７３－３３．７３和１３．５６－２５．７４ｍｇＣＯ２ｄｍ＾－２ｈ＾－１，内膛短枝叶的光合速率为４．５５－９．９０ｍｇＣＯ２ｄｍ＾－２ｈ＾－１。５月下旬至８月下旬的两年连续测定表明，盛果期大树外围新梢叶的光合速率高于外围短枝叶。短枝叶的光合速率在５月份呈现最高值。６月份及以     

黔油10号制种高产栽培模式分析

采用田间试验和定量分析的方法研究了黔油１０号制种产量与栽培措施的数量关系,建立了数学模型并作了增产效应分析及有关措施的优化组合,研究结果表明,施用尿素：１０．０～２５．８ｋｇ／６６７ｍ＾２,种植密度：１．４～１．８万株／６６７ｍ＾２。氯化钾;２．５～６．０ｋｇ／６６７ｍ＾２,过磷酸钙;３６．０～５０ｋｇ／６６７ｍ＾２,可望获得７５～１００ｋｇ／６６７ｍ＾２的籽粒产量。     

鲁德1号冬小麦耐盐力分析

以坝４１３１为母本，运麦１３为父本进行有性杂交育成的鲁德１号冬小麦，在耕层盐分３－７ｇ／ｋｇ的盐碱地上平均每６６７ｍ＾２产１７８．２ｋｇ。在各省试验结果表明，鲁德１号比对照品种德选１号增产１７．０５％－６２．１８％。抗逆性强主要表现在产量构成因素合理，叶片功能期长，对Ｋ＾＋的选择性吸收和运输能力强，降低了植株体内Ｎａ＾＋／Ｋ＾＋比值。可在盐渍土地大力推广。     

不结球白菜紫色叶片花青素相对含量的遗传分析

为研究不结球白菜[Brassica campestris L. ssp. chinensis (L.) Makino var. communis Tsen et Lee]叶片紫色性状的遗传规律,选用紫色和绿色不结球白菜亲本纯系各一个配制正反交组合,并构建该杂交组合的6 个世代群体（P1、P2、F1、B1、B2和F2）,利用分光光度计在540 nm处测定6 世代家系的不结球白菜叶片花青素相对含量,最后花青素相对含量的遗传规律采用多世代联合的数量性状分离分析方法研究。结果表明：不结球白菜杂交组合后代的花青素相对含量介于2 个亲本之间,呈现出多峰或单峰偏态分布,且偏向于紫色亲本。其遗传模式符合2 对加性-显性-上位性主基因+加性-显性-上位性多基因模型（E-0模型）;其中F2 的主基因遗传率为59.17%,多基因遗传率为27.58%,环境方差占表型方差的比例为19.48%;B1（F1×紫）的主基因遗传率为74.12%。环境因素对不结球白菜花青素相对含量存在一定的影响,因此建议在光照充足及温度适宜的秋季,且在分离早期世代进行不结球白菜紫叶性状的遗传选择,其中B1的遗传效率较高。     

高粱靶斑病菌侵染对高粱光系统Ⅱ的影响

以高粱品种Tx622B为试验材料,通过测定叶片叶绿素含量、叶绿素荧光快速诱导动力学曲线、过氧化氢(H2O2)含量和丙二醛(MDA)含量,来研究高粱靶斑病菌[Bipolaris sorghicola(Lefebvre&Sherwin)Alcorn]侵染高粱叶片后对光系统II(PSII)结构和功能的影响。结果表明,受病原菌侵染的高粱叶片,H2O2和MDA含量均升高,膜脂过氧化的程度加剧;快速叶绿素荧光诱导动力学曲线发生明显变化,进一步的JIP测试分析表明病原菌侵染严重伤害了PSII供体侧,阻断了受体侧QA到QB的电子传递,降低了反应中心的活性。     

Response of Rice (Oryza sativa L.) Tillering to Sub-ambient Levels of Ultraviolet-B Radiation

The negative impact of enhanced ultraviolet‐B (UV‐B) radiation has been demonstrated for rice, but few studies have examined the effects of low UV‐B radiation on rice growth and physiology. The objective of this study was to determine the effects of low UV‐B radiation on rice physiology with special emphasis on tiller initiation and development in two popular US rice cultivars, ‘Cocodrie’ and ‘Clearfield 161 (CL161)’. Plants received no natural UV‐B radiation because of the UV‐absorption characteristics of the greenhouse glass, hence UV‐B was artificially supplied by supplemental UV‐B lighting. Plants were grown in soil collected from research plots, and were exposed to UV‐B radiation of 0, 4 (sub‐ambient) or 8 kJ m⁻² day⁻¹ (ambient) for 29 days in one experiment and 87 days in a second experiment. ‘Cocodrie’ had no differential response among 0, 4 and 8 kJ m⁻² day⁻¹ UV‐B treatments for all the parameters measured except for plant height, which showed 5% decrease at ambient UV‐B conditions. For ‘CL161’ sub‐ambient UV‐B radiation exposure decreased vegetative tiller production (25%) and total panicle dry weight (15%). The decrease in tiller production was not due to a decrease in carbohydrate content or increase in auxin content under the low UV‐B radiation.     

钙处理对白菜生长发育及货架寿命的影响

以白菜为试材,研究了不同浓度氯化钙对其生长特性及货架寿命的影响。结果表明:(1)低浓度钙处理能促进白菜的生长发育,提高其产量,其中以0.25?Cl2处理效果最好;(2)钙处理可明显降低白菜腐烂率,增加组织中钙的含量,抑制白菜的膜脂过氧化作用,降低质膜透性和呼吸强度,延长白菜的货架寿命。其中以1.0?Cl2处理延缓组织衰老腐烂效果最好。     

根肿病(Plasmodiophora brassicae)菌侵染对大白菜幼苗叶片膜脂过氧化的影响

旨在研究根肿病菌侵染过程中膜脂过氧化相关指标及保护酶类活性的变化。以感病（91-12B）和抗病（CR91-12B）大白菜为试验材料,采用注射法对其进行接菌,取样测定。91-12B和CR91-12B抗氧化酶类活性均表现为先升高后降低,但抗病CR91-12B对病菌胁迫反应迅速,防御及时,活性氧系统处于动态平衡。感病91-12B对病菌胁迫反应慢,防御不及时,活性氧系统平衡被破坏。这说明接菌后,抗病材料能及时产生超氧阴离子作为信号激发细胞的抗氧化反应。同时发现,接菌后第8天为抗病CR91-12B对病菌胁迫产生反应的时间。本试验验证了根肿病抗性与膜脂过氧化间的关系,为一些生长调节剂和人工合成的活性氧清除剂在抗根肿病上的应用提供了依据;     

补光时间和光质对温室甜椒叶片生长、碳代谢的影响

为探究发光二极管(LED)补光对温室甜椒叶片生长及碳代谢的影响,以甜椒品种‘奥黛丽’为试材,设置红光(R)和蓝光(B)组合2:1(2R1B)、4:1(4R1B)、8:1(8R1B)3种光质,2 h(18:00—20:00)、4 h(18:00—22:00)和8 h(18:00—次日02:00)3个补光时间,以不补光为对照(CK),研究补光时间及光质对甜椒叶片生长、元素含量、糖含量及碳代谢关键酶活性的影响。结果表明,光质与补光时间能显著影响甜椒叶片的生长及碳代谢,且两者之间存在交互作用。与CK相比,光质2R1B处理的比叶重、钾、果糖、淀粉含量显著降低;而光质4R1B和8R1B处理的叶片数、总叶面积、叶绿素总量、生物量净积累速率(NAR)、总糖含量及酸性转化酶(AI)、中性转化酶(NI)和蔗糖合成酶(SS)活性显著高于CK,且8R1B处理略优于4R1B处理,说明红光比例增大有利于叶片生长和碳代谢;光质对甜椒叶片氮、磷、钾、镁元素的含量影响不显著。除光质2R1B处理外,在同一光质下,随着补光时间的延长,甜椒的叶片数、比叶重、叶面积指数(LAI)、NAR、总糖、果糖、淀粉含量及AI、NI、SS...     

高温胁迫对景天植物膜脂过氧化及保护酶活性的影响

研究高温胁迫对景天植物的膜脂过氧化程度及保护酶活性的影响。以5种景天植物为试材,进行45℃/30℃（白13 h/昼11 h）高温胁迫,高温胁迫前及胁迫后每5天取叶片测定相关生理指标,分析膜脂过氧化程度及保护酶活性的变化。随着高温胁迫程度加重,5种景天植物的O2.-产生速率和MDA含量持续上升,耐热性强的景天植物O2.-产生速率上升慢、MDA含量积累少;胁迫过程中,5种景天植物的SOD、POD、CAT活性均高于胁迫前,说明高温胁迫诱导3种酶活性增强,3种酶活性在整个胁迫过程中呈现先升后降的趋势,耐热性强的景天植物SOD、POD、CAT活性增幅高。高温胁迫下通过增强SOD、POD、CAT活性以减轻膜脂过氧化程度是景天植物适应高温胁迫的重要生理机制。     

Methyl Jasmonate Counteract UV-B Stress in Barley Seedlings

The role of exogenously applied phytohormone methyl jasmonate (MeJA) in counteracting the ultraviolet B (UV‐B) stress in barley seedlings was investigated. Barley seedlings (Hordeum vulgare L., cv. Alfa) 4 days old were supplied with 5 × 10^?5 m MeJA through the roots for 3 days and then exposed for 2 days for 5 h per day to UV‐B (312 nm, biological effectiveness of UV‐B radiation 28.8 kJ m^?2day^?1). The rate of ¹⁴CO₂ fixation, PSI and PSII activities and chlorophyll content decreased, but flavonoids, H₂O₂, malondialdehyde, proline and UV‐B induced compounds increased after UV‐B treatment. The rate of photosynthetic oxygen evolution was more strongly inhibited by UV‐B‐irradiation than PSI and PSII efficiency. MeJA itself increased the content of free proline, which acts as a stress protector due to its radical scavenging ability. Increased superoxide dismutase, catalase and peroxidase (POX) activities in the leaves and in the roots and the POX isoforms induction revealed the MeJA involvement in plant tolerance to oxidative stress caused by UV‐B irradiation. It was shown that pre‐treatment with MeJA counteracted UV‐B stress. Therefore, it was suggested that MeJA could acts as a mediator in plant defense responses to UV‐B irradiation by enhancing the activity of antioxidant system and free radical scavenging capability of plant cells.     

根施外源多胺抑制剂MGBG和D-ARG对小麦幼苗抗旱性的影响

在25%PEG-6000模拟干旱胁迫下,使用MGBG(1 mmol/L)、D-ARG(1 mmol/L)、L-ARG(1 mmol/L)处理二叶期的小麦根系72 h,结果表明,MGBG和D-ARG降低叶片相对含水量,增强叶片的膜脂过氧化作用,促进叶片和根系的生长,而L-ARG对叶片的含水量影响不大,促进根系的生长,促进叶片膜脂过氧化作用。这些表明,外源多胺抑制剂MGBG和D-ARG抑制根系多胺的形成不利于叶片水分的维持。     

Decay of the Chloroplast Pool of Ascorbate Switches on the Oxidative Burst in UV‐B‐Irradiated Rice

A parallel was drawn between UV‐B irradiation and the oxidative burst in the chloroplast lamellae of rice plants (Oryza sativa L. cv. Safari). After irradiation with a total biological effective UV‐B of 20.825 kJ m^?2 between the 15th and 21st days following germination, it was found that superoxide, hydroxyl radicals and hydrogen peroxide increased significantly in stressed leaves. The levels of ascorbate and the kinetics of superoxide dismutase, glutathione reductase, dehydroascorbate reductase, ascorbate peroxidase and catalase became increasingly inhibited. The developing oxidative burst also diminished photosynthetic pigments and galactolipids accumulation, while the de‐epoxidation state of xanthophylls and lipids peroxidation increased. Following grana disorganisation, the accumulation of chloroplast polypeptides having 72/69, 33/32, 28/26, 22/20 and 18/16 kDa decreased, but the relative proportion of the 49/46 kDa polypeptides increased. The 69/65 kDa polypeptides also diminished on the 15th day. These alterations implicated the failure of both photosystems functioning, but the inhibition of the Hill reactions coupled to the water splitting complex was uppermost. In the 28th day, the chloroplast lamellae of leaves grown after UV‐B exposure revealed a general recovery from oxidative burst and a subsequent higher stacking of thylakoids. It is concluded that UV‐B irradiation becomes lethal when ascorbate oxidation in the xanthophyll cycle limits the antioxidant enzymes kinetics, triggering chloroplast proteolysis and acyl lipid peroxidation because of reactive oxygen species propagation.