论文总字数：16839字

摘 要

钾是所有植物正常生长所必需的重要营养素之一，它对于维持各种植物的正常生长发育和植物的抗逆性能都有着重要的作用。我国土壤中可以被植物吸收利用的可溶性钾资源非常匮乏，但是我国拥有大量的以钾长石为主的难溶性钾矿资源。研究表明，土壤中存在一种将难溶性钾转化为可溶性钾的解钾菌，同时解钾菌还能分泌多种植物激素，促进植物的生长，改善土壤环境。因此，从土壤中筛选出解钾效率钾高的高效解钾菌具有很重要的现实意义。本试验从南京工业大学校内采集多处的土壤，最终筛选出一株名为J2020KNX-11的高效解钾菌，并对其对水稻幼苗的促生作用进行了研究。

采用稀释涂布平板法，利用初筛培养基筛得10株菌株，对其进行纯化培养，再利用摇瓶释钾进行复筛，最终获得一株解钾率为11.3%的J2020KNX-11的菌株，并研究得出最佳碳源为葡萄糖，最佳氮源为牛肉膏，最佳培养条件为30℃，PH=7，1.5%接种量培养32h。以水稻幼苗为供试植物，用J2020KNX-11的培养液对其浇灌，结果表明：稀释100倍浓度的解钾菌菌液对水稻苗的促生效果最明显，跟对照相比，对水稻苗的株高、根长、鲜重、干重、叶绿素增涨幅度分别为37.15%、6.56%、10.00%、9.30%、59.88%。

从研究结果来看，J2020KNX-11号解钾菌具有一定的解钾活性，将其接种到土壤中，对植物有一定的促生作用，能够显著提高植物的各形态指标和物质含量指标，其有望能被开发成生物肥料并应用到农业生产中。

关键词：解钾菌 钾元素 水稻幼苗 促生功效

Screening of high efficiency potassium-releasing bacteria and its effect on rice seedling growth promotion

Abstract

Potassium is one of the important nutrients necessary for the normal growth of all plants. It plays an important role in maintaining the normal growth and development of various plants and the stress resistance of plants. The soluble potassium resources that can be absorbed and used by plants are very scarce in China's soil, but there are a large number of refractory potassium mineral resources mainly composed of potash feldspar. Studies have shown that there exists in soil a kind of potassium decomposers which can convert insoluble potassium into soluble potassium, and at the same time the potassium decomposers can secrete a variety of plant hormones to promote the growth of plants and improve the soil environment. Therefore, it is of great practical significance to select high-efficient potassium-releasing bacteria with high potassium-releasing efficiency from the soil. In this experiment, a strain named j2020knx-11 was selected from the soil of Nanjing tech university, and its effect on promoting growth of rice seedlings was studied.

By using dilution coated tablet, at the beginning of using sieve medium from 10 strains, purification, to reuse after screen shaker potassium release, eventually get a strain of the rate of 11.3% between J2020KNX-11 strains, and study the best carbon source is glucose, the best nitrogen source for the beef extract, optimum culture conditions of 30 ℃, PH = 7 32 h,1.5% quantity of training. Rice seedlings were taken as test plants and irrigated with the culture solution J2020KNX-11. The results showed that the potassium solution diluted at a concentration of 100 times had the most obvious effect on the growth of rice seedlings. Compared with the control, the plant height, root length, fresh weight, dry weight and chlorophyll growth of rice seedlings were 37.15%, 6.56%, 10.00%, 9.30% and 59.88% respectively.

According to the results of the study, no. J2020KNX-11 potassium-releasing bacteria has certain potassium-releasing activity, which can be inoculated into the soil to promote the growth of plants, and can significantly improve the morphological indexes and material content indexes of plants. It is expected to be developed into biological fertilizers and applied in agricultural production.

Key words: potassium bacteria; potassium; rice seedling; plant growth promoting

目录

摘要 1

Abstract 2

一．前言 5

1.1钾肥施用现状 5

1.2土壤中钾的作用 6

1.2.1 钾在土壤中的形式 6

1.2.2钾对农作物影响 7

1.3解钾菌 8

1.3.1 解钾菌的解钾、促生机理 9

1.3.2 解钾菌的研究进展 10

1.4 研究目的及意义 11

二． 实验材料与方法 12

2.1 实验仪器及试剂 12

2.1.2培养基 12

2.2 解钾菌的初筛 12

2.2.1样品采集 12

2.2.2菌株的分离和保存 13

2.3 高效解钾菌的复筛 13

2.4 培养条件优化 13

2.5 高效解钾菌的促生初步研究 13

2.5.1 培养条件及步骤 13

2.5.2各指标的测定 14

三．结果与分析 14

3.1 高效解钾菌的筛选 14

3.1.1初筛 14

3.1.2复筛 14

3.1.3解钾菌J2020KNX-11培养条件的优化 15

3.2 高效解钾菌对水稻幼苗的促生作用 18

3.2.1 对水稻幼苗形态上的作用 18

3.2.2 对水稻幼苗物质含量的测定 19

四．讨论 20

参考文献 21

五．致谢 23

一．前言

1.1钾肥施用现状

据统计，我国目前已发现40处可溶性钾盐矿产地，其大部分分布于青海，西藏等偏远地区，经济储量约为800万吨，可供开采时间为4年，储备量为4.5亿吨，占世界的2.5%^[1]。依照目前我国开采的速度，我国的钾肥可供开采66年^[2]。

虽然我国的可溶解性钾资源匮乏，但是我国拥有大量的难溶性的以钾长石为基础钾矿资源，总储量约100亿吨。因此，目前解决我国钾资源匮乏的重要方法就是将难溶性的钾矿转化为可溶性钾。现阶段，将难溶性钾矿转化为可溶性钾主要有以下几种工艺：（1）水热化学法：通过水热化学反应，以钾长石为原料形成钾硅钙复合矿物肥料。刘善科等^[3]利用水化学反应破坏钾长石的三维骨架结构，将钾、硅、铝等水溶性物质释放出来。（2）焙烧法：在一定温度条件下，将钾矿石与助剂混合焙烧，形成可溶性钾盐。陈定盛等^[4]采用Na₂SO₄作为助剂，得到了92～94%的钾溶出率。（3）微生物法：将钾长石粉与解钾菌剂混合发酵，制成含有可溶性钾的微生物肥料。虽然化学方法转化难溶性钾矿效率高，但是其能耗高，环境污染严重，成本高，而使用微生物法，成本低，污染小，工艺简单，具有更好的发展前景。

1.2土壤中钾的作用

1.2.1 钾在土壤中的形式

在土壤学中，依据钾元素在土壤中对作物的有效性，分为缓效钾，速效钾和无效钾；依据化学形态可分为结构钾、水溶性钾和交换性钾 ^[5]。

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