Phosphorus in plant physiology P content of plants Approximately 0.2% of plant dry weight is P Plants require a relatively large amount of P. The phosphate concentration in the cytosol is maintained at fairly constant concentrations in the 5 to 8 mol/m3 regardless of the external phosphate concentration except under severe P deficiency. By contrast is the vacuolar phosphate concentration

Acknowledge I expresses thanks to Assoc. Prof. rob Reid of Adelaide university of Australia, Dr Jeff Gale, foreign teacher of northwest A&F University of China, and Prof. Zhang Fusuo, Prof. Li Xiaolin of China Agriculture University, Prof Liu Yuanyin of Northeast agriculture Unversity and other authors who provide materials for me, or whose materials, such as photographs and figures etc, I used in the lectures

Concept of plant nutrition Plant nutrition is a term that takes into account the interrelationships of mineral elements in the growth medium as well as their role in plant growth

Scope of this lecture Root functions: for plant, soil and ecosystem Root structure and pathways for uptake of nutrients the symplast and apoplast Root architecture(结构) and morphology(形态) Responses of roots and root systems to environmental stress Root hairs and their functions Introduction to combined strategies for efficient

Aims of this lecture Summarize properties of the rhizosphere, especially Gradients in Nutrient concentration Redox potential Exudates Microbial activity Non-infecting rhizosphere microorganisms Infecting rhizosphere microorganisms that are relevant to plant mineral nutrition red from H Marschner:

一、保护生物学的定义 保护生物学是刚刚诞生十多年的一门新兴学科。近半个世纪以来,由于社会 迈入后工业文明的历史阶段,人类已经领悟到,我们居住的地球正在进入一个动 植物物种空前大量灭绝的时代,而灭绝对人类的未来是可怕的,人类必需扭转这 种趋势。为此,一门危机学科一—保护生物学应运而生。鉴于紧迫的社会需求、 大量的研究素材与课题、丰厚的科学基金与资助,以及期刊《保护生物学》的问 世,使保护生物学很快成为一门世人瞩目的前沿学科

第一节常规杂交育种的意义和杂交方式 第二节有性杂交技术 第三节杂交后代的选择

水稻是我国主要粮食作物之一,种植面积在全国居于第一位,占全国耕地 面积的14,年产量占全国粮食总产的1/2。但是,水稻病害的危害严重地影响 着我国的水稻生产。尽管人们一直在积极探讨各种方法对水稻病害进行防治, 每年减产仍高达200亿kg。因此,防治水稻病害对我国的农业可持续发展,农 村稳定和农民生活水平的提高都具有极其重要的战略意义

稻曲病又称假黑穗病、绿黑穗病、青粉病、谷花病、“丰收病”等。我国早在明朝李时 珍的《本草纲目》中便有指稻曲病菌子实体为“粳谷奴”的记载。该病在亚洲、美洲和非 洲的30多个国家及我国各稻区都有不同程度发生

稻瘟病在我国明代宋应星的《天工开物》(1637年)一书中便有记载。目前是世界性 分布、危害最重的病害之一,尤其在东南亚、日本、韩国、印度和我国发生特别严重流 行年份,一般发病田块损失在10%~30%左右如不及时防治,局部田块会颗粒无收。 症状 稻瘟病在整个水稻生育期都有发生,根据受害时期和部位不同,可分为苗瘟、叶瘟、 叶枕瘟、节瘟、穗瘟、穗颈瘟、枝梗瘟和谷粒瘟