问题 问答题 简答题

光照对花卉生长发育的影响。

答案

参考答案:

(一)光照强度对花卉的影响

光照强度常依地理位置以及云量、雨量的不同而变化,其变化是有规律的:一般来说,光照强度随着纬度的增加而减弱,随着海拔的升高而增强。一年中夏季光照最强,冬季光照最弱;一天中以中午光照最强,早晚光照最弱。光照强度不同,不仅直接影响光合作用的强度,而且还影响到一系列形态上和解剖上的变化,如叶片的大小和厚薄;茎的粗细、节间的长短;叶肉结构以及花色浓淡等等。另外,不同的花卉种类对光照强度的反应也不一样,多数露地草花,在光照充足的条件下,植株生长健壮,着花多,花也大;而有些花卉,如玉簪、铃兰、万年青等在光照充足的条件下生长极为不良,在半荫条件下才能健康生长。花卉之间需光亮的差异是由花卉的原产地光照特点决定的。如热带高原光照强度大,原产与此地的花卉需光亮较大,喜阳光充足环境。热带雨林中由于湿度高,阳光被分散吸收,光照强度不大,原产于此处花卉大多比较耐阴,是室内植物的主要来源。

1.光照强度影响一些花卉种子的萌发

2.光照强度影响花卉的营养生长和形成建成

3.光照强度影响花卉花蕾的开放

4.光照强度影响花色

(二)光照长度对花卉的影响

1.光照长度影响一些花卉的营养繁殖

2.光照长度影响花卉的冬季休眠

3.光照长度决定一些花卉的成花过程

(三)光的组成(光质)对花卉的影响

红橙光有利于植物碳水化合物的合成,加速长日照植物的发育,延长短日照植物的发育。蓝紫光抑制茎的伸长,促进花青素的形成,有利于蛋白质的合成,加速短日照植物的发育,抑制长日照植物的发育。

(四)光的调节

(一)光照强度对花卉的影响

光照强度常依地理位置以及云量、雨量的不同而变化,其变化是有规律的:一般来说,光照强度随着纬度的增加而减弱,随着海拔的升高而增强。一年中夏季光照最强,冬季光照最弱;一天中以中午光照最强,早晚光照最弱。光照强度不同,不仅直接影响光合作用的强度,而且还影响到一系列形态上和解剖上的变化,如叶片的大小和厚薄;茎的粗细、节间的长短;叶肉结构以及花色浓淡等等。另外,不同的花卉种类对光照强度的反应也不一样,多数露地草花,在光照充足的条件下,植株生长健壮,着花多,花也大;而有些花卉,如玉簪、铃兰、万年青等在光照充足的条件下生长极为不良,在半荫条件下才能健康生长。花卉之间需光亮的差异是由花卉的原产地光照特点决定的。如热带高原光照强度大,原产与此地的花卉需光亮较大,喜阳光充足环境。热带雨林中由于湿度高,阳光被分散吸收,光照强度不大,原产于此处花卉大多比较耐阴,是室内植物的主要来源。

1.光照强度影响一些花卉种子的萌发

2.光照强度影响花卉的营养生长和形成建成

3.光照强度影响花卉花蕾的开放

4.光照强度影响花色

(二)光照长度对花卉的影响

1.光照长度影响一些花卉的营养繁殖

2.光照长度影响花卉的冬季休眠

3.光照长度决定一些花卉的成花过程

(三)光的组成(光质)对花卉的影响

红橙光有利于植物碳水化合物的合成,加速长日照植物的发育,延长短日照植物的发育。蓝紫光抑制茎的伸长,促进花青素的形成,有利于蛋白质的合成,加速短日照植物的发育,抑制长日照植物的发育。

(四)光的调节

光照强度通过补光和遮荫网等来调节;光照长短可以使用黑布和黑塑料布遮光减少日照时间,用电灯延长日照时间。光质可通过选用不同的温室覆盖物来调节。

阅读理解

阅读理解。

   

     In winter, when the sun hides behind the clouds,everyone feels a bit low. You may be tired and find

you want to sleep all the time. What you may not know is:you are suffering from (患有) SAD (季节性抑郁症).

     But don't worry-it's normal. Colder temperatures and fewer hours of daylight can steal your energy and

put you in a bad mood.

     Read on to find out what SAD is and what you can do to help yourself or those around you.

     These days, Linda,a US teenager spends most of her holidays sleeping instead of doing sports outside.

She has also had trouble concentrating (集中精力) on her homework. When her mother asks her what's

wrong,Linda doesn't know what to tell her. Linda may not realize it yet, but she's suffering from SAD. It

causes people to sleep,eat sweet food and get sad or angry for no reason.

     About 15 percent of American people now suffer from SAD in winter according to the US Department

of Health. The US government has taken measures to help people beat it. Local communities encourage

people to take part in activities such as exercise,dance or art. And they advise people not to eat too much

sweet food.

     Like in the US, cold northern European countries such as Finland, Iceland and Russia see a large number

of people suffer from SAD every year. So, the sunlamp is widely used in these countries. It's an electric lamp

which is just like a "little sun" that gives off light to make people think the sun is shining and feel better.

1. Colder ________ and less ________ are the main causes of SAD.

2. Linda is feeling ________ and doesn't ________ doing sports because she's suffering from SAD.

3. Suffering from SAD is ________ in northern European countries in ________.

4. In some northern European countries, the ________ is widely used to make people feel ________.

5. Taking an active part in ________ and eating ________ sweet food can help people beat.

选择题