问题 问答题 简答题

简述日光温室冬春茬茄子嫁接换根的意义和方法。

答案

参考答案:

1.嫁接的意义

茄子易受黄萎病、青枯病、立枯病、根结线虫病等土传病害的危害,不能重茬,需5~6年轮作。采用嫁接育苗,不但可以有效地防治黄萎病等土传病害,使连作成为现实,而且由于根系强大,吸收水肥能力强,植株生长旺盛,具有提高产量、品质,延长采收期的作用。

2.嫁接方法

(1)砧木选择。目前生产中使用的砧木多是从野生茄子中筛选出来的高抗或免疫品种,如托鲁巴姆。

(2)播种。托鲁巴姆不易发芽,可用150~200mg/L的赤霉素溶液浸种48h,置于日温35℃,夜温15℃的条件下,8~10d可发芽。播种时由于托鲁巴姆种子拱土能力差,覆盖2~3mm厚的药土即可,二叶一心时移入营养钵中。当砧木苗子叶展平,真叶显露时播接穗。茄子种子发芽较慢,可采用变温催芽的方法,即一天中25~30℃8h,10~20℃16h交替进行,使发芽整齐,5~6d即可出齐。茄子黄萎病在苗期就能侵入到植株体内,潜伏到门茄瞪眼期发病,播种接穗时必须进行土壤消毒,并用塑料薄膜将育苗营养土与下部土壤隔开,防止病菌侵入。

(3)嫁接。砧木具8~9叶,接穗具6~7叶,茎粗达0.5cm开始嫁接。生产中多采用劈接法,即用刀片在砧木2片真叶以上平切,去掉上部,然后在砧木茎中间垂直切入1.0~1.2cm深。而后迅速将接穗苗拔起,在接穗半木质化处(幼苗上2cm左右的变色带,即半木质化处),两侧以30°向下斜切,形成长1cm的楔形,将削好的接穗插入切口中,用嫁接夹固定好。

(4)接后管理。利用小拱棚保温保湿并遮光,3d后逐渐见光。嫁接10~12d后愈合,伤口愈合后逐渐通风炼苗。茄苗现大蕾时定植。

单项选择题
单项选择题

Anthropology is the study of human beings as creatures of society. It (1) its attention upon those. physical characteristics and industrial techniques, those conventions and values, which (2) one community from all others that belong to a different tradition.

The distinguishing mark of anthropology among the social sciences is that it includes for serious study other societies (3) our own. For its purposes any social (4) of mating and reproduction is as significant as our own. To the anthropologist our customs and those of a New Guinea tribe are two possible social schemes for (5) a common problem, and in so far as he remains an anthropologist he is (6) to avoid any weighting of one (7) the other. He is interested in human behavior, not as it is shaped by one tradition, our own, but as it has been shaped by any tradition (8) He is interested in a wide (9) of custom that is found in various cultures, and his object is to understand the way in which these cultures change and (10) , the different forms through which they express themselves and the (11) in which the customs of any peoples function in the lives of the (12) .

Now custom has not been commonly regarded as a (13) of any great moment. The inner workings of our own brains we feel to be uniquely (14) of investigation, but custom, we have a way of thinking, is behavior at its most commonplace. (15) , it is the other way round. Traditional custom is a mass of detailed behavior more astonishing than (16) any one person can ever evolve in individual actions. Yet that is a rather (17) aspect of the matter. The fact (18) first rate importance is the predominant role that custom (19) in experience and belief, and the very great varieties it may (20)

8()

A.however

B.though

C.whatsoever

D.indeed