一个新的大豆细胞质黄化突变体的初步研究

用一个大豆叶片黄化突变体与6个带有不同标记基因的基因型杂交配制了8个杂交组合(包括两组正反交组合)。根据杂交后代的表现对该突变体进行了遗传分析并测定了亲本和F_1植株的叶绿素含量。结果表明该突变体的叶绿素缺失性状呈母体遗传。当以黄化突变体为母本时,杂交F_1和F_2单株都表现为黄化,当用正常的非黄化基因型作为母本时,所有的F_1和F_2植株都不黄化。在自然光照条件下,突变体的叶绿素a、叶绿素b和总叶绿素含量约是正常基因型的47.4、40.4和43.7％。突变体新生叶片的叶绿素含量很低,随着叶片的发育成熟,叶绿素含量逐渐接近正常基因型。根据大豆遗传委员会的有关规定和惯例,建议将该突变体定名为Cyt—Y_4。     

Differences in Response to Iron Deficiency Among Some Lines of Common Bean

Abstract

Five dry bean cultivars (Coco blanc, Striker, ARA14, SVM29‐21, and BAT477) were evaluated for their resistance to iron deficiency on the basis of chlorosis symptoms, plant growth, capacity to acidify the external medium and the root‐associated Fe³⁺‐reduction activity. Plants were grown in nutrient solution supplied or not with iron, 45 µM Fe(III)EDTA. For all cultivars, plants subjected to iron starvation exhibited Fe‐chlorosis. These symptoms were more severe and more precocious in BAT477 and Coco blanc than in the others cultivars. An important acidification of the culture medium was observed between the 4th and the 8th days of iron starvation in Striker, SVM29‐21 and, particularly, ARA14 plants. However, all Fe‐sufficient plants increased the nutrient solution pH. This capacity of acidification appeared more clearly when protons extrusion was measured in 10 mM KCl + 1 mM CaCl₂. The above genotypic differences were maintained: ARA14 showed the higher acidification followed by Coco blanc and BAT477. Iron deficiency led also to an increase of the root‐associated Fe(III)‐reductase activity in all lines. However, genotypic differences were observed: Striker shows the highest capacity of iron reduction under Fe deficiency condition.     

Iron deficiency Chlorosis in peppers

A yellow‐fruited inbred pepper cv. ‘Zehavi’, was found to be highly chlorotic on a previously non‐cultivated calcareous soil in the Arava Valley (Israel) during winter 1981–1982. Foliage symptoms and a test for diagnosing iron indicated iron deficiency, soil application of Fe EDTA corrected the symptoms in the field. When ‘Zehavi’ was sown at the same location, in the winter of 1982–1983, but on calcareous soil which had previously been cultivated for several years, no chlorosis appeared. Inheritance studies indicated recessive control for iron deficiency chlorosis but complete genetic interpretation is suggested only under controlled iron deficiency conditions.     

果树叶盐酸提取铁与叶失绿关系的研究

本文研究了果树正常绿叶和失绿黄叶中用盐酸提取的铁,Fe#+（2+）和全量铁之间的差异。结果表明,在一定提取条件下果树正常绿叶中的全量铁和用盐酸提取的铁之间存在着一定的数量平衡,在桃叶中二者的比率稳定在2.1左右;失绿黄叶中全量铁和绿叶的含量一样或高于绿叶,但用盐酸提取的铁以及Fe#+（2+）则明显比绿叶少,全量铁和盐酸提取铁比率显著增大;失绿叶中K和P的含量比绿叶高而Ca含量则比绿叶低。叶片中的K和Fe含量呈负相关。     

苹果树缺铁失绿研究的进展 Ⅱ.铁逆境对树体形态及生理生化作用的影响

本文根据最近研究进展对缺铁失绿苹果植株在形态、结构、生理生化等方面所起的变化如细胞超微结构、光合作用、呼吸作用、叶绿素含量和根系还原铁的能力等以及抗缺铁失绿基因型选择加以论述。     

转FRO2基因番茄突变体的抗缺铁黄化特性

为了增加植物的抗缺铁黄化能力,研究了转FRO2基因番茄突变体抗黄化特性．结果显示FRO2基因转化番茄后,使生长在缺铁胁迫下的植株根系铁还原酶活性大大增强（转FRO2基因番茄植株根系酶活性是对照2倍）,番茄铁吸收能力和有效铁还原能力大大加强,植株中有效铁含量增加（转FRO2基因番茄植株叶片有效铁含量是时照的1．5倍）,转FRO2基因番茄的植株叶片颜色显著比对照绿,黄化程度减轻,黄化指数降低（对照的黄化指数是转FRO2基因番茄的1．3倍）,植株生长量显著高于对照（转基因植株株高高于对照50％）．在正常条件下,转FRO2基因番茄根系的FRO2基因表达量增加,铁还原酶活性增加了1．75倍,转FRO2基因番茄植株叶片有效铁含量是对照植株的2倍,是其他耐贮藏转基因番茄的（转反义NR、ACC、CTR1基因）2～3．5倍以上．     

Fe Chelates for Remediation of Fe Chlorosis in Strategy I Plants

Abstract

Iron chlorosis is a mineral disorder due to low Fe in the soil solution and the impaired plant uptake mechanism. These effects increased with high pH and bicarbonate buffer. The solution to Fe chlorosis should be made by either improving the Fe uptake mechanism or increasing the amount of Fe in the soil solution. Among Fe fertilizers, only the most stable chelates (EDDHA and analogous) are able to maintain Fe in the soil solution and transport it to the plant root. In commercial products with the same chelating agent, the efficacy depends on the purity and the presence of subproducts with complexing activity, that can be determined by appropriate analytical methods such as HPLC. In commercial products declaring 6% as Fe‐EDDHA, purity varied from 0.5% to 3.5% before 1999, but in 2002 products ranging 3–5.4% chelated Fe are common in the Spanish market. Fe‐o,p‐EDDHA, as a synthesis by‐product with unknown efficacy, is present in all Fe‐EDDHA formulations. Commercial Fe‐EDDHMA products also contain methyl positional isomers. Fe‐EDDHSA synthesis produces condensation products with similar chelating capacity to the Fe‐EDDHSA monomer that can account for more than 50% of the chelated iron in the commercial products. Chelates with different molecules should be compared for their efficacy considering firstly their ability to maintain Fe in solution and secondly their capacity to release iron to the roots. Accepting the turnover hypothesis, their efficacy is also dependent thirdly on the ability of the chelating agent to form the chelate using native iron from the soil. The 1st and 3rd points are related to the chemical stability of the chelate, while plants make better use of iron from the less stable chelates. Plant response is the ultimate evaluation method to compare commercial products with the same chelating agent or different chelates.     

不同铁制剂对石灰性土壤条件下猕猴桃缺铁黄化的矫治效果

为明确陕西杨凌渭河滩地猕猴桃出现黄化现象的原因,通过对喷施铁制剂矫正效果的比较,筛选出理想的铁制剂用于果树缺铁黄化病防治。以陕西杨凌西桥村出现缺铁黄化的猕猴桃园为研究对象,采用土壤诊断和叶片诊断等方法确定黄化的原因,并以清水为对照,喷施不同铁制剂(硫酸亚铁、柠檬酸铁、复合氨基酸铁、乳酸亚铁和腐殖酸铁)进行矫治,检测其对猕猴桃叶片叶绿素和有效铁含量及果实品质的影响。结果表明,猕猴桃黄化原因不仅仅是由于土壤有效铁含量低,还与植株吸收能力不同有关。由于植株过多吸收P、K、Zn、Mn等元素,引起养分不平衡而导致对铁吸收产生拮抗作用也是产生缺铁黄化的原因之一。不同铁制剂对猕猴桃黄化的矫治效果有差异,其中以柠檬酸铁和复合氨基酸铁的处理效果最好,显著提高了猕猴桃叶片的叶绿素和有效铁含量以及果实中维生素C、可溶性固形物、全铁的含量,有效改善了果实品质。在供试的几种铁制剂中,柠檬酸铁和复合氨基酸铁是矫治果树缺铁黄化的最理想制剂。     

Uptake of Iron (59Fe) Complexed to Water‐Extractable Humic Substances by Sunflower Leaves

Abstract

A research was carried out to evaluate the leaves' ability to utilize Fe supplied as a complex with water‐extractable humic substances (WEHS) and the long‐distance transport of ⁵⁹Fe applied to sections of fully expanded leaves of intact sunflower (Helianthus annuus L.) plants. Plants were grown in a nutrient solution containing 10 µM Fe(III)‐EDDHA (Fe‐sufficient plants), with the addition of 10 mM NaHCO₃ to induce iron chlorosis (Fe‐deficient plants). Fe(III)‐WEHS could be reduced by sunflower leaf discs at levels comparable to those observed using Fe(III)‐EDTA, regardless of the Fe status. On the other hand, ⁵⁹Fe uptake rate by leaf discs of green and chlorotic plants was significantly lower in Fe‐WEHS‐treated plants, possibly suggesting the effect of light on photochemical reduction of Fe‐EDTA. In the experiments with intact plants, ⁵⁹Fe‐labeled Fe‐WEHS or Fe‐EDTA were applied onto a section of fully expanded leaves. Irrespective of Fe nutritional status, ⁵⁹Fe uptake was significantly higher when the treatment was carried out with Fe‐EDTA. A significant difference was found in the amount of ⁵⁹Fe translocated from treated leaf area between green and chlorotic plants. However, irrespective of the Fe nutritional status, no significant difference was observed in the absolute amount of ⁵⁹Fe translocated to other plant parts when the micronutrient was supplied either as Fe‐EDTA or Fe‐WEHS. Results show that the utilization of Fe complexed to WEHS by sunflower leaves involves an Fe(III) reduction step in the apoplast prior to its uptake by the symplast of leaf cells and that Fe taken up from the Fe‐WEHS complexes can be translocated from fully expanded leaves towards the roots and other parts of the shoot.     

不同配比的木醋肥对香樟林土壤性状的影响

将不同配比的木醋肥施用于香樟林地中,通过测定施肥后林地土壤微生物数量、酶活性、土壤部分化学性质以及植物黄化相关指标的变化情况,旨在选择效果明显的配比应用于城市绿地绿化植物的养护中.试验结果表明,6种试验配方均能不同程度地改善香樟林土壤性状,主要表现在:微生物数量增加、酶活性提高、化学性质得到改良,同时香樟黄化也得到有效控制.低浓度木醋液中加入低量有机肥,对土壤微生物有一定的抑制作用,并且化学性质和黄化改良效果不如其他处理明显;从生产应用、使用价值等综合效果来看,中低浓度木醋液中加入木炭粉(木醋液∶木炭粉比例为1∶5(V∶M))和中高量有机肥的处理改良效果最好.