陆地棉新的黄绿苗突变体浙12—12N叶绿素含量与净光合速率研究

黄绿苗浙１２─１２Ｎ与美国芽黄等突变体的芽黄性状差异明显、苗期真叶叶绿素含量也迥然不同，黄绿苗浙１２─１２Ｎ的子叶和苗期真叶均呈现淡黄色、叶绿素ａ＋ｂ、ａ、ｂ的含量及ａ／ｂ比值各为１．２３５５ｍｇ／ｇ、０．７９３３ｍｇ／ｇ、０．４４２２ｍｇ／ｇ鲜叶和１．７９９１，分别比常绿苗的泗棉２号低３３。３２％、３４．３３％、３１．４４％和３．８９％；较苗色浅黄至黄色的Ｔ５８２、Ｖ１、Ｖ２、Ｖ３高１４．２６％～５８．２４％、１４．７９％～６５．５９％、１３．３２％～４５．０５％和２．０３％～５９．２６％。在棉铃吐絮前、黄绿苗浙１２─１２Ｎ的上部主茎叶及果枝新出叶仍然显现淡黄色、各叶位叶片叶绿素含量呈现由上而下递增趋势，主茎顶端完全展开叶、倒二叶的叶绿素含量极显著地低于泗棉２号、斯字棉７０１Ｎ，但倒五叶及其以下各叶的叶绿素含量反而较常绿色品种高。其各叶位叶片的净光合速率不同程度地高于泗棉２号，且水分利用率和无能利用率高。     

观赏羽衣甘蓝生长期植物光合色素变化规律

为探究对羽衣甘蓝成色机理中植物光合色素的变化规律,本研究以7种国内外观赏羽衣甘蓝为材料,进行内外叶的叶绿素a、叶绿素b和类胡萝卜素含量的测定.对不同品种、不同生长期进行比较,分析叶绿素a/b、类胡萝卜素与叶绿素总量的比值.结果 表明,在生长期,观赏羽衣甘蓝外叶的叶绿素总含量呈下降趋势,内叶的变化无规律性,且外叶的叶绿素总含量大于内叶.不同品种之间、同一品种的外叶与内叶之间的叶绿素含量存在显著差异.外叶、内叶的类胡萝卜素含量变化规律相反,外叶为下降趋势,内叶为上升趋势.在幼苗期至转色期,观赏羽衣甘蓝叶绿素a/b比值为2.53～3.31,类胡萝卜素与叶绿素总含量的比值为0.11～0.30.在观赏期、抽薹期,观赏羽衣甘蓝外叶的叶绿素a/b比值小于3,内叶的比值大于3,内叶的类胡萝卜素与叶绿素总含量的比值均大于外叶.通过探究观赏羽衣甘蓝叶片生长期光合色素变化规律,为羽衣甘蓝的新品种选育提供基础理论依据,并为彩叶植物在园林绿化的应用做出实践指导.     

观赏羽衣甘蓝生长期植物光合色素变化规律

为探究对羽衣甘蓝成色机理中植物光合色素的变化规律,本研究以7种国内外观赏羽衣甘蓝为材料,进行内外叶的叶绿素a、叶绿素b和类胡萝卜素含量的测定.对不同品种、不同生长期进行比较,分析叶绿素a/b、类胡萝卜素与叶绿素总量的比值.结果 表明,在生长期,观赏羽衣甘蓝外叶的叶绿素总含量呈下降趋势,内叶的变化无规律性,且外叶的叶绿素总含量大于内叶.不同品种之间、同一品种的外叶与内叶之间的叶绿素含量存在显著差异.外叶、内叶的类胡萝卜素含量变化规律相反,外叶为下降趋势,内叶为上升趋势.在幼苗期至转色期,观赏羽衣甘蓝叶绿素a/b比值为2.53～3.31,类胡萝卜素与叶绿素总含量的比值为0.11～0.30.在观赏期、抽薹期,观赏羽衣甘蓝外叶的叶绿素a/b比值小于3,内叶的比值大于3,内叶的类胡萝卜素与叶绿素总含量的比值均大于外叶.通过探究观赏羽衣甘蓝叶片生长期光合色素变化规律,为羽衣甘蓝的新品种选育提供基础理论依据,并为彩叶植物在园林绿化的应用做出实践指导.     

棉花不同生育期SOD同工酶与品种抗黄萎病性相关性的研究

凝胶电泳测定不同棉花品种子叶期、４叶期、蕾期、铃期、吐絮期等５个不同生育期的叶片内ＳＯＤ同工酶,结果其谱带数目相应为４、８、８、４、３,随着棉花的生育进程,ＳＯＤ同工酶活性由弱一强一弱。在棉花生长前期子叶期、４叶期,抗、感黄萎病品种之间,接菌与不接菌棉株间,ＳＯＤ同工酶谱活性差异不明显;在蕾期,虽然品种间的ＳＯＤ同工酶谱活性差异不明显,但接菌的棉株Ｅ１、Ｅ５、Ｅ６三条酶带活性强于不接菌棉株,Ｅ３活性则相反;在铃期,抗、耐品种较感病品种Ｅ２谱带活性强,接菌棉株较不接菌棉株增加一条Ｅ３ｂ谱带。感病品种泗棉２号上显症棉株叶片体内ＳＯＤ同工酶较无病症叶增加一条Ｅ４酶带;不同病级的叶片内,ＳＯＤ同工酶的活性差异不大。至吐絮期,不同品种棉株及显症叶与无病叶间的ＳＯＤ酶活性又趋相同。     

棉花化学杀雄剂1号对棉花吸收矿质营养元素的影响

棉花叶片喷施化学杀雄剂１号后，叶片中Ｃａ２＋、Ｍｎ２＋、Ｆｅ２＋的含量在 ０～３ｄ内有较大幅度下降，３～７ｄ内有较小幅度上升，第二次用药后的变化趋势与第一次用药类似，１２ｄ后Ｍｎ２＋下降了２５％，Ｆｅ２６＋下降了２３％，Ｃａ２＋下降了４０％；棉叶中Ｍｇ２＋、Ｚｎ２＋及总氮（Ｎ）的含量受杀雄剂的影响不明显；Ｂ的含量在０～５ｄ内单调下降，后趋于稳定。在杀雄剂中加入金属离子（Ｚｎ２＋、Ｃｕ２＋、Ｍｎ２＋、Ｍｇ２＋）后，棉叶和整株中Ｂ、Ｎ的含量提高了；棉叶中Ｃａ２＋的含量无提高的趋势；棉叶中Ｍｎ２＋的含量在０～３ｄ内明显上升，３～７ｄ内又明显下降。在杀雄剂中加入 Ｂ，有利于提高棉叶中 Ｆｅ２＋和Ｃａ２＋的含量。     

外源硒对茶树叶片硒含量、抗氧化酶及光合色素的影响

本文以一年生‘舒茶早’和‘龙井43’盆栽扦插苗为材料，根际和叶面分别施入亚硒酸钠，测定不同叶位硒含量、抗氧化酶活性和叶片光合色素含量。结果表明：‘舒茶早’第1、2叶总硒含量根施比清水对照高5.2倍，叶施比对照高482倍；‘龙井43’根施比对照高13.68倍，叶施高706.5倍。总硒含量不同叶位差异显著，1—2叶>第3—4叶>第5—6叶>第7—8叶>第9—10叶。根施和叶施两种施硒方式均可提高茶树叶片中SOD、POD、CAT、APX活性。根际施硒后‘舒茶早’叶片叶绿素a、叶绿素b、类胡萝卜素含量分别比清水对照高20.20%、17.73%、22.99%，叶施后高29.48%、29.78%、32.53%。‘龙井43’的叶绿素a，叶绿素b，类胡萝卜素含量根施分别比对照高1.18%、2.17%、0.86%，叶施比对照降低19.44%、19.15%、13.33%。     

Zn和EDTA对紫花苜蓿叶片光合特性的响应

为了探索提高紫花苜蓿的抗锌能力,以3个紫花苜蓿品种为试材,采用土培法,研究Zn胁迫(250μg/kg)下,EDTA对不同品种紫花苜蓿叶片锌富集量、光合色素含量及叶绿素荧光参数的影响。结果表明,在50 d时,紫花苜蓿叶片Zn的含量均显著增高,Zn+EDTA显著提高了苜蓿叶片对锌的吸收;大叶苜蓿品种叶片光合色素的含量高于对照,大叶苜蓿叶绿素a、叶绿素b、总叶绿素和类胡萝卜素的含量显著高于其他2个品种;EDTA处理可提高大叶苜蓿初始荧光值、可变荧光、最大荧光值、最大光化学效率的水平。结果显示,EDTA促进大叶苜蓿叶片的光合色素含量的增加,减少过剩激发能的耗散,提高光合电子传递效率,有效降低锌胁迫对紫花苜蓿叶片PSⅡ的伤害,提高大叶苜蓿的抗锌能力。     

金叶榆不同叶位叶片呈色生理机制研究

通过测定金叶榆不同叶位叶片的色素含量和光合生理参数,旨在研究其叶片的呈色生理机制。结果表明,叶绿素a、b含量从顶梢向下逐渐升高,类胡萝卜素、花青素含量及色差参数L、a、b值逐渐降低;净光合作用速率显著升高,叶位7以下的叶片高达12μmolCO2/(m²·s)以上,而顶梢叶位1没有光合产物积累;单位面积进入用于电子传递的量子产额ETO/CS提高,光量子的热耗散比率DIO/CS降低;最大光量子效率提高,叶位9以下的叶片Fv/Fm在0.8以上;叶位12、11的性能指数、光合驱动力明显高于上部的叶片,与对照白榆没有明显差异。试验发现,金叶榆叶片色彩与类胡萝卜素含量成极显著正相关关系,叶片色彩受光照条件和光合作用状态调控,说明金叶榆叶片色彩是一种生态表现型。     

杂种小麦光合特性的初步研究

对化杀型杂种小麦与普通小麦叶光合特性的比较研究表明，供试杂种小麦上部叶片倒３叶、旗叶一生中比普通小麦对照品种具有较高的叶绿素含量、净光合速率。ＲｕＢＰｃａｓｅ活性和ＲｕＢＰｏａｓｅ活性。杂种小麦叶片与对照相比在叶绿素含量缓解（ＲＳＰ）上优势较小，光合速率高值持续期（ＰＡＤ）和ＲｕＢＰｃａｓｅ含量则不具有优势。这表明，杂种小麦上部叶一生中光合速率的提高受到ＲｕＢＰｃａｓｅ含量的影响较小，而在很大程度     

水稻叶氮量等生理参数的叶位分布特点及其与氮素营养诊断的关系

以氮素营养特性差异较大的3个品种为材料,研究了水稻不同生育期顶部4片展开叶中叶片总氮、叶绿素和游离氨基酸及叶鞘总氮含量的叶位分布特点。各生育期叶片和叶鞘总氮含量均以顶1叶最高,而游离氨基酸和叶绿素的最高含量叶位随品种和生育期而异。抽穗前游离氨基酸的最高含量叶位随品种和生育期变化较大,而抽穗后以顶1叶含量     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.