多胺在小麦种子萌发初期的变化和作用

本试验以小麦种子为材料，研究了种子萌发初期内源ＰＡｓ含量的变化及结合外源ＰＡｓ、ＰＡｓ合成抑制剂Ｄ－ａｒｇ和ＡＢＡ研究ＰＡｓ在种子萌发初期的效应。结果表明：小麦种子萌发初期内源ＰＡｓ尤其Ｐｕｔ大量增加。在三种不同浓度外源ＰＡｓ中，０．０１￣１ｍＭＰｕｔ对种子萌发的促进效应最明显，Ｓｐｄ仅在０．０１ｍＭ有一定促进效应。但不显著，Ｓｐｍ在试验浓度范围内都有抑制效应。外源ＰＡｓ合成抑制剂Ｄ－ａｒｇ和ＡＢ     

温度对Olsen法测定潮土速效磷的影响和校正方法的探讨

探讨了温度对Ｏｌｓｅｎ法测定潮土速效磷的影响，结果表明，撮温度和速效磷浸出量之间呈极显著正相关，这种影响又与土壤速效磷贮量有关。根据统计分析得出比率（Ｐ２５／Ｐ１）与温度之间的有关参数，确定了包含土壤磷素水平影响在内的１０￣３０℃温度范围的经验校正式：Ｐ２５＝Ｐｔ（Ａ＋Ｂｔ）经检验，不同土样任意温度下测定值的校正值与２５℃时测定值无显著差异，符合试验要求。     

不同供磷水平小麦苗期根系特征与其相对产量的关系

研究了缺磷条件下不同基因型小麦苗期根系形态学及生理学适应特征 ,结果表明 :在缺磷环境中 ,小麦根轴数量和侧根长度明显减小 ,同化物向根部的分配比例增加 ,根轴长度、侧根数量和根系长度等均是显著提高。供试基因型小麦的根轴数量及其长度的差异在每个供磷水平及不同供磷水平之间均是显著的 ,说明这两种性状的差异是由基因型和环境因素共同决定的 ;而侧根特征的差异只在不同供磷水平之间是显著的 ,表明侧根性状主要是受环境因素控制的。对 6种基因型小麦的研究表明 ,高磷水平的小麦种子根的生长角度明显低于低磷处理的小麦 ,根角之间存在着显著的基因型差异。在缺磷条件下 ,6种基因型小麦完整根系分泌的酸性磷酸酶活性、根轴数量、根轴长度、根生长角度和根系长度之间均存在着显著的基因型差异。相关分析表明 ,缺磷条件下的小麦苗期根系形态指标和根系分泌的酸性磷酸酶活性的交互作用与小麦的相对产量之间具有显著的线性关系 ,这种关系说明以上 5种性状均可作为早期有效地筛选磷高效小麦品种的指标     

旗叶期缺磷及去蘖对小麦光合特性和磷分配的影响

采用石英砂培养方法并去除或保留分蘖，研究了旗叶期缺磷对大穗型小麦CA9325和多穗型晋麦2号（JM2）生长后期旗叶光合和蒸腾速率、干物质和磷在体内分配以及最终产量的影响。结果表明: ⑴旗叶期缺磷一段时间后降低小麦旗叶的光合和蒸腾速率。不同供磷水平下，去蘖使小麦旗叶光合和蒸腾速率大都高于同期未去蘖的；⑵旗叶期缺磷几乎导致两品种所有器官和整株干物质和磷的积累降低，去蘖的小麦籽粒干物质和磷总量占整株的比例均高于未去蘖的，说明缺磷促进小麦各营养器官的磷向籽粒转移；⑶主茎干物质和磷的积累以CA9325高于JM2，而JM2则以分蘖占优势，这与JM2分蘖数较多有关；⑷ 不论供磷还是缺磷，未去蘖的CA9325籽粒产量低于JM2，而去蘖后则相反。不同库容量的CA9325千粒重和籽粒磷含量均高于JM2。全生育期供磷条件下的磷吸收效率，以未去蘖的CA9325显著高于JM2，去蘖后两品种间无明显差异。     

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     

小麦磷素营养和磷素的营养诊断

小麦的生长发育对磷素表现敏感,其土壤磷的临界值要比玉米和大豆分别高出1~2倍,植株体内的磷浓度与子粒产量有十分密切的关系。目前,土壤缺磷或磷肥供应不足是不少地区小麦高产的主要障碍因子,磷肥的施用效果与众多条件有关。本文就小麦     

不同基因型冬小麦幼苗对缺锌的敏感性反应

采用砂培试验研究了不同小麦基因型对施锌的反应.通过比较小麦幼苗根冠比的大小(是否大于1),以及根据培养过程中植株的生长表现,将供试的25种小麦基因型划分为两类:即缺Zn敏感型和非敏感型.结果还表明,供Zn可以促进小麦地上部和根系的生长,均较大幅度提高了叶绿素SPAD值(25个小麦基因型中18个的增幅都超过10%),而根冠比则相对保持稳定.小麦种子中的锌含量、幼苗根冠比与小麦叶片叶绿素SPAD值之间均无显著性相关关系.由于地上部积累了较高浓度的Zn,缺Zn非敏感型可有效减轻缺Zn对其造成的危害.非敏感型与敏感型相比较,缺Zn条件下地上部和根系锌含量平均值分别高出96.6%和28.8%,而在供Zn条件下则高出47.6%和10.9%.施Zn对敏感型与非敏感型小麦体内磷含量并无显著性影响.小麦幼苗中P/Zn的大小主要受到小麦体内Zn含量变化的影响,与磷含量则无明显的关系.     

不同耐低磷水稻基因型秧苗对难溶性磷的吸收利用

选取4个典型耐低磷水稻基因型99011、508、580和99112,并以2个磷敏感基因型99012和99056为参照,采用营养液培养和砂培的方法,研究不同磷处理对秧苗生长的影响以及不同耐低磷基因型对3种难溶性磷源(有机磷、铝磷和磷矿粉)吸收利用能力的差异。结果表明,不同无机磷处理,6个基因型生物量和根干重基本上均为全磷处理（P）>对照+铝磷（CK+Al-P）>对照+磷矿粉（CK+RP）> 对照（CK）;4个耐低磷基因型根干重和根冠比均大于2个磷敏感基因型;对于根冠比,耐低磷基因型580和99011为对照+磷矿粉（CK+RP）>对照+铝磷（CK+Al-P）> 对照（CK）> 全磷处理（P）,耐低磷基因型508、99112和磷敏感基因型99012为CK> CK+RP> CK+Al-P > P,磷敏感基因型99056为CK+Al-P > CK+RP > P>CK;缺磷处理,秧苗活化吸收难溶性磷源的能力均为OP> Al-P> RP,且不同基因型的分解吸收能力对OP为99011> 508> 580> 99012> 99112> 99056（表2）,对Al-P为580> 99011> 99112> 508> 99056> 99012（表3）,对RP为580> 99112> 99011> 508> 99012> 99056（表2）。此外,缺磷即CK处理,508对低浓度的磷吸收最多(表2和表3),而580对磷的利用效率显著高于其他基因型（表3）,这些特征可能也是它们耐低磷的重要贡献因子之一。     

小麦氮、磷高效新品系的鉴定和评价

提高肥料利用效率、降低施肥量是农业可持续发展迫切需要解决的问题。为鉴定和培育氮、磷高效新品系,设置正常、低氮和低磷3个养分处理进行营养池栽培试验,以济麦22为对照,对12个自育小麦品系进行氮、磷效率鉴定和评价。以氮、磷效率指数对供试材料进行评价,鉴定出4个氮、磷双高效品系和6个磷高效品系;以籽粒氮、磷利用效率对供试材料进行评价,发现正常氮和低氮条件下的氮高效品系有2个,分别是JK60871和JK64109;低磷条件下有7个品系的籽粒磷利用效率高于对照10%以上,正常磷条件下磷利用效率在品系间的差异不明显。综合以上2种评价结果,JK60871为相对稳定的氮、磷双高效品系,JK60787、JK61879、JK61593、JK64109、JK61560和JK61574为相对稳定的磷高效品系。     

缺磷胁迫对不同玉米幼苗生长的影响

营养液砂培4种不同玉米自交系材料,设置0.25mol/LKH2PO4全磷(对照)、0mol/LKH2PO4(缺磷)两种处理,于5、7、9、11d时考察幼苗生长指标。对缺磷胁迫下4种不同基因型玉米自交系生长的研究表明,低磷胁迫对040651、044191地上部分的抑制大于根系,根系的相对干生物量明显高于地上部分的相对干生物量;从相对株高和相对叶面积的研究显示,编号为040651的自交系受缺磷胁迫的影响小于其他3个自交系材料。缺磷胁迫下4种不同基因型玉米自交系根系形态的研究显示:缺磷胁迫诱导玉米根伸长,根系表面积增大,根冠比显著增加。     

缺锌条件下小麦的养分吸收状况及不同基因型的耐性差异

采用螯合-缓冲营养液（Chelator-buffer culture solution）进行培养试验,对缺锌条件下3种小麦基因型（绵阳19、邯6172、新麦13）的生长发育状况及对P、Cu、Fe、Mn营养的影响进行了研究,并且应用4种指标,即锌效率（缺锌与锌充足供应条件下小麦地上部干物质之比）、相对冠根比（缺锌与锌充足供应条件下小麦冠根比之比）、缺锌条件下小麦地上部的锌吸收量、干物质量,对3种小麦的耐缺锌能力进行了比较。结果表明,在锌缺乏条件下小麦地上部生长量明显降低,而根系依然能保持相对较强的生长发育能力;不同小麦基因型对缺锌的耐性存在明显差异,其中邯6172的耐性最强;在缺锌胁迫条件下,小麦地上部Cu、Fe、Mn含量及Cu／Zn、Fe／Zn、Mn／Zn均明显升高,地上部锌含量与Cu、Fe、Mn含量均呈极显著负相关,说明锌缺乏能够促进Cu、Fe、Mn在地上部的累积。与此相反,锌缺乏条件下小麦P含量及吸收量均明显降低,地上部磷、锌含量之间极显著正相关,但与Cu,Fe,Mn相似,缺锌后P从根系向地上部的转运率升高。同时,对缺锌耐性最强的小麦基因型邯6172在锌缺乏条件下,地上部Cu、Fe、Mn含量的升高与P含量的降低幅度均是3种供试小麦中最大的,似乎表明小麦对锌缺乏的耐性大小与对Cu、Fe、Mn的吸收能力及与对P吸收的抑制有关。     

Morphological and physiological differences in the response of cereals to zinc deficiency

Greenhouse and growth chamber experiments were carried out using seven bread wheat (Triticum aestivum), three durum wheat (T. durum), two rye (Secale cereale), three barley (Hordeum vulgare), two triticale (x Triticosecale Wittmack) and one oat (Avena sativa) cultivars to study response to zinc (Zn) deficiency and Zn fertilisation in nutrient solution and in a severely Zn deficient calcareous soil. Visual Zn deficiency symptoms, such as whitish-brown necrotic patches on leaf blades, developed rapidly and severely in the durum wheat and oat cultivars. Bread wheat showed great genotypic differences in sensitivity to Zn deficiency. In triticale and rye, visual deficiency symptoms were either absent or appeared only slightly, while barley showed a moderate sensitivity. When grown in soil, average decreases in shoot dry matter production due to Zn deficiency were 15% for rye, 25% for triticale, 34% for barley, 42% for bread wheat, 63% for oat and 65% for durum wheat. Differential Zn efficiency among and within cereal species was better related to the total amount of Zn per shoot, but not to the Zn concentration in the shoot dry matter. However, in leaves of Zn efficient rye and bread wheat cultivars, the activity of Zn-containing superoxide dismutase was greater than in Zn inefficient bread and durum wheat cultivars, suggesting higher amounts of physiologically active Zn in leaf tissue of efficient genotypes. When grown in nutrient solution, there was a poor relationship between Zn efficiency and release rate of Zn-chelating phytosiderophores from roots, but uptake of labelled Zn (⁶⁵Zn) and its translocation to the shoot was higher in the Zn efficient rye and bread wheat cultivars than in inefficient bread and durum wheat cultivars. The results demonstrate that susceptibility of cereals to Zn deficiency decline in the order durum wheat > oat > bread wheat > barley > triticale > rye. The results also show that expression of high Zn efficiency in cereals was causally related to enhanced capability of genotypes to take up Zn from soils and use it efficiently in tissues. This revised version was published online in August 2006 with corrections to the Cover Date.     

锌胁迫对不同耐低磷玉米生长及磷、锌养分吸收的影响

用营养液培养方法研究了不同耐低磷玉米幼苗对缺锌胁迫的适应性差异.结果表明,低磷敏感基因型在缺锌时植株各部位锌含量和吸收量显著下降,且变幅均明显高于耐低磷基因型.缺锌处理影响玉米幼苗的磷含量,低磷敏感基因型地上部磷含量较对照显著上升,根系磷含量变幅不大;耐低磷基因型地上部磷含量变幅较小,根系磷含量则显著下降.低磷敏感基因型在缺锌时地上部磷利用率显著下降,根系磷利用率无明显变化,而耐低磷基因型的变化情况正好相反,根系磷利用率受影响的程度大于地上部.     

Effects of Zinc Deficiency and Drought on Grain Yield of Field-grown Wheat Cultivars in Central Anatolia

Drought stress and zinc (Zn) deficiency are serious abiotic stress factors limiting crop production in Turkey, especially in Central Anatolia. In this study, the effects of Zn deficiency and drought stress on grain yield of 20 wheat cultivars (16 bread wheat, Triticum aestivum; four durum wheat, Triticum durum cultivars) were investigated over 2 years under rainfed and irrigated conditions in Central Anatolia where drought and Zn deficiency cause substantial yield reductions. Plants were treated with (+Zn: 23 kg Zn ha⁻¹, as ZnSO₄·7H₂O) and without (−Zn) Zn under rainfed and irrigated conditions. Both Zn deficiency and rainfed treatments resulted in substantial decreases in grain yield. Significant differences were determined between both bread wheat and durum wheat cultivars in terms of drought stress tolerance. Considering drought sensitivity indices over 2 years, the bread wheat cultivars Yayla‐305, Gerek‐79, Dagdas‐94 and Bolal‐2973 were found to be more drought‐tolerant than the other cultivars under both −Zn and +Zn treatments. Especially the durum wheat cultivars Cakmak 79 and Selcuklu 97 showed much greater drought susceptibility under Zn deficiency, and irrigation alone was not sufficient to obtain satisfying grain yield without Zn application. The results indicate that sensitivity to Zn deficiency stress became more pronounced when plants were drought‐stressed. The effect of irrigation on grain yield was maximized when Zn was adequately supplied, leading to the suggestion that efficient water use in Central Anatolia seems to be highly dependent on the Zn nutritional status of plants.     

Differential tolerance to Fe and Zn deficiencies in wheat germplasm

Tolerance to Fe deficiency of wheat genotypes exhibiting differential tolerance to Zn deficiency is not known, even though the relationship between Fe nutrition and differential tolerance of wheat genotypes to Zn deficiency has been hypothesised frequently. In the present experiment, eight Triticum aestivum and two T. turigidum L. conv. durum cultivars were grown in nutrient solution deficient in either Znor Fe. Three indices of tolerance to nutrient deficiency were compared: relative [(-nutrient/+nutrient) × 100] shoot growth, shoot dry weight under nutrient deficiency and relative shoot/root dry weight ratio. Genotypes Aroona, Excalibur, Stilleto and Trident were classified as tolerant to both Zn and Fe deficiency, while durum wheats Durati and Yallaroi were sensitive to Zn deficiency and moderate to sensitive to Fe deficiency. Genotypes Excalibur, Stilleto and Trident come from the same breeding programme and have the common parent (line MEC3 =Sonora64//TZPP/YAQUI54) that could have been the donor of the genes for tolerance to Zn deficiency. When Fe-deficient, all wheat genotypes were severely chlorotic but kept producing shoot and root dry matter at a relatively high rate, making the relationship between the relative shoot growth and the relative leaf chlorophyll content poor. This is the first report of wheat genotypes exhibiting multiple tolerance to Zn and Fe deficiencies. This revised version was published online in July 2006 with corrections to the Cover Date.     

用激光剥蚀电感耦合等离子体质谱研究小麦籽粒元素的共分布

增加粮食可食用部分微量营养元素的浓度, 需要更好地了解其在植株, 特别是籽粒内的运输和分布规律。激光剥蚀电感耦合等离子体质谱(laser ablation inductively coupled plasma mass spectrometry, LA-ICP-MS)是一种测定植物组织中元素空间分布的新技术。采用该技术对成熟小麦籽粒中锰(Mn)、铜(Cu)、锌(Zn)和磷(P)的空间分布及其关联程度定量研究。结果表明, 所测元素在籽粒不同部位的浓度分布差异很大。Cu、Zn和P浓度均以糊粉层最高, 胚乳最低, 胚居中, 浓度最大差异分别达15、42和33倍; Mn浓度则以胚最高, 胚乳最低, 糊粉层居中, 浓度最大差异达9倍。籽粒同一部位不同位置的元素浓度亦不相同, 外周胚乳(靠近糊粉层)的元素浓度大于内侧胚乳部位对应元素的浓度, 胚最外侧盾片部位的元素浓度大于胚中间位置的元素浓度, 且各元素趋势一致。比较分析发现, 麦粒不同部位元素的浓度变化存在明显的同步性, 籽粒中P浓度高的部位金属元素(Mn、Cu和Zn)浓度也高。这说明不同元素在向籽粒不同部位运输和积累过程中可能存在密切关联性。     

小麦不同生育期磷-锌关系研究

采用田间试验方法,在土壤中施用不同水平组合的磷、锌肥,在小麦的不同生育时期(苗期、拔节期、抽穗期、灌浆期以及成熟期)分器官对磷-锌营养关系进行了研究.结果表明,施磷降低了小麦地上部各器官锌含量,且水平越高效果愈明显,在作用时间上主要表现在生长前期(苗期、拔节期和抽穗期);小麦苗期、拔节期和成熟期地上部各器官磷含量在施锌...     

锌胁迫对三种柑橘砧木的生理特性和锌分配的影响

为了探究锌胁迫对柑橘砧木生长的影响,本文采用溶液培养的方法,测定了不同锌浓度如0 mg?L-1(锌缺乏)、0.005 mg?L-1(锌低量)、0.05 mg?L-1(锌适量)、0.5mg?L-1(锌过量)条件下枳壳、酸橙与红橘的相关生理指标及不同部位锌含量变化。结果表明：1）锌胁迫显著抑制了枳壳及酸橙的生长,而对红橘生长的影响较小。2）与锌适量处理相比,锌缺乏和锌低量处理时枳壳、酸橙根系POD活性均明显降低,各锌处理间红橘根系CAT活性无显著性差异;锌胁迫下三者叶片与根系脯氨酸含量均显著高于适量锌处理,不同锌处理下枳壳叶片MDA及其根系脯氨酸含量均相对低于酸橙与红橘。3）随着锌处理浓度的升高,三者根、茎、叶的锌含量均趋上升,且根系锌含量显著较高。锌过量处理下三者的叶/根、叶/茎、茎/根比均显著低于其他锌处理。可见,三种柑橘砧木对锌胁迫的反应存在明显的差异。     

抗旱剂拌种处理对小麦萌发和幼苗生长的影响

干旱胁迫下用抗旱剂Ⅰ号拌种处理小麦种子可以提高小麦出苗率，促进根系发育，增加根冠比。处理后，幼苗的生理生化指标均高于对照，可使幼勒在较低水势下保持正常生长。