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     

钙提高水稻耐盐性的研究

在０．５％ＮａＣｌ盐胁迫下，适当增加外界Ｃａ＾２＋浓度，可显著降低水稻体内Ｎａ＾＋含量，减少Ｎａ＾２＋由根向地上部的净运输率，并提高植株相对生长率。但Ｃａ＾２＋作用大小受介质中Ｎａ＾＋与Ｃａ＾２＋两者之比值的制约，最适Ｎａ／Ｃａ比值为２０和５０。Ｃａ＾２＋的减少（即Ｎａ／Ｃａ比值＝１０００）或过多（即Ｎａ／Ｃａ比值＝５）都导致了水稻盐害进一步加剧。钙还可以明显降低叶片和根系的质膜透性，并提高根质膜     

对中综3号玉米群体格子混合选择效果分析

用格子混合选择法完成了对中综３号玉米群体６轮的产量性状的选择,兼顾抗性、株型、早熟性等性状。经１９９５～１９９６年在北京、安徽、河南２年３点联合试验,结果表明,６轮群体子粒产量每ｈｍ＾２增加了１１５５ｋｇ（２４．０５％）,平均每轮每ｈｍ＾２增加１９２．４５ｋｍ（４．０１％）,与线性回归响应（ｂ＝１８７．８ｋｇ）相吻合。子粒产量增加的主要原因是单株穗部性状发生了变化。穗长每轮增加１．８ｃｍ（１２．７％）,每行粒数增加４．１粒（１０．９％）,千粒重增加２７．２ｇ（１２．５％）,差异均达极显著水平。同时,株高、穗位也有所提高。经６轮选择后,株高增加２９．２ｃｍ。抗倒性、抗青枯等显著提高,倒伏率从Ｃ０的２２．７％减少到Ｃ６的１２．１％,青枯病株率从Ｃ０的１８．１％减少到Ｃ６的９．６％。     

湘南冬闲稻田小黑麦高产栽培技术研究

小黑麦高产栽培技术试验研究表明，通过选用良种，适时早播，加强肥水管理等措施可明显提高小黑麦产量。通过３年试种，筛选出产草高，抗性好，生育期适中，耐寒耐瘠薄，适应湘南冬闲稻田大面积种植的小黑麦品种ＯＨ１６２１和Ｈ１８８１，ＯＨ１６２１适时早播（１０月２９日播种与１１月１８日播种比较）可使小黑麦增产鲜草１９３８６ｋｇ／ｈｍ＾２，增幅为１１５．２％；有机肥、无机肥配合（ＮＰＫ＋Ｍ）比单纯化肥（ＮＰＫ）１０７６５．５ｋｇ／ｈｍ＾２，增幅４９％．比单施有机肥（ＯＭ）增产鲜草１１６０５．５ｋｇ／ｈｍ＾２，增幅５５．０％。     

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     

小麦穗层整齐度的遗传研究

通过对２０个小麦品种（系）两年的试验研究，明确了小麦穗层整齐度是一个遗传性状。该性状在品种（系）间存在明显的遗传变异，ｇｃｖ＝１１．９９％；遗传力较高，ｈＢ＾２＝８２．５％。穗层整齐度与产量呈弱正相关，遗传相关系数ｒｇ＝０．３７８１；与株高呈极显著正相关，遗传相关系数ｒｇ＝０．７６８７。     

三高甜菜颗粒粕饲料喂羊试验

研制三高甜菜颗粒粕饲料，克服了普通甜菜颗粒粕的营养缺陷，提高了饲用价值。通过小群与生产性大群试验，表明三高颗粒粕饲料能促进幼龄羊生长发育，体长与胸围的增长达到极显著水平（Ｐ＜０．０１），增重提高３０．１３％－３４．１６％，增重效果极显著（Ｐ＜０．０１）。每公斤增重可节省草料１．２８－１．３０ｋｇ，能量和蛋白质的消耗分别减少１６．２％－１８．８％和１２．６％－１６．８％，经济效益显著地高于对照组，具     

京效地区小麦,玉米两茬间氮,磷,钾肥的合理施用

在京郊不同土壤肥力条件下，进行小麦，玉米两茬间氮，磷，钾肥合理施用的研究。三年多点试验结果表明，全年氮素投入０．０３６－０．０４８ｋｇ／ｍ＾２，以小麦，玉米各半或玉米居多为宜。冬小麦施氮在下茬玉米上无明显后效。冬小麦适宜施氮量为０．０２４ｋｇ／ｍ＾２，夏玉米适宜施氮量０．０３０ｋｇ／ｍ＾２，冬小麦和夏玉米施磷肥不仅对当季有增产作用，而且对下茬作物也有明显的后效。冬小麦施Ｐ２Ｏ５ ０．０１５ｋｇ／ｍ     

不同温度下施用钾肥对玉米生长及磷钾养分吸收的影响

在砂培试验中，设置了０、１．５、４．０ｇ／ｋｇ Ｋ２Ｏ施钾水平，３个施磷水平保持一致（０．１０ｇ／ｋｇＰ２Ｏ５），玉米分别在网室（低温）及温室（常温）中生长，待玉米长至５叶期时测定植株的钾磷吸收状况，结果表明，温室及网室中玉米生长因施钾而受到显著影响，以施用１．５ｇ／ｋｇＫ２Ｏ最有利于玉米地上部及根的生长，而其中又以网室（低温）中的生长促进效果更为显著。无论是在温室还是在网室中，施用钾肥均使玉米植     

冬绿肥品种及播量试验初报

通过苏箭三号、白花早茹，６６－２５三个绿肥品种及播量分别为４．０，４．５，５．０，５．５，６．０ｋｇ／６６７ｍ＾２的试验表明遵义市以苏箭三号鲜草产量最高，其次为白花早苕，６６－２５最低；在净作条件下三个品种播量以５．５ｋｇ／６６７ｍ＾２最为适宜。     

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.     

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.     

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.     

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.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.