Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/21458
標題: 缺水對玉米、大麥生理與產量的影響
THE EFFECTS OF WATER DEFICIENCY ON THE PHYSIOLOGY AND YIELD OF MAIZE AND BARLEY
作者: 陳琇瑜
CHEN, XIU-YU
關鍵字: 環境因子;ENVIRONMENTAL-FACTOR;氣象條件;抗旱生理;WEATHER-COMDITION;DROUGHT-RESISTANCE;PHYSIOLOGICAL;BIOCHEMICAL
出版社: 植物學研究所
摘要: 
Water is one of the important environmental factors that effect plant
growth. In Taiwan, the cultivations of field crops are often failed by
the water stress due to the geographical and weather conditions.
Therefore, it is necessary to understand the response of plants under
water stress condition, and the relationship between drought-resistance
and yield capacity for the purpose of improving the rotation system of
cultivated crops.
In the present experiment maize and barley were used as the
materical. The following physiological and biochemical programs were
studied:
1.The growth and physiology of photosynthesis of expanded leaves.
2.The significance of the changes in amount of sulutes inside
expanding leaves and the growth functions under the condition water
deficits and rewatering after water shortage.
3.The observations of the root/shoot ratio and the leaf size by using
soil-sand culture under eaterstress condition. Moreover, to find
out the possible factors which inhibited the leaf elongation
4.To search for the effects that water stress exerted on yield
component of various crops.
The results were summarized as follows:
1. The water potential and osmotic potential of expanded leaf of maize
and barley displayed significant diurnal varivation under control
and mild stress (-0.8 ~ -1.5 Mpa). The diurnal pattern of the
osmotic potential of expanded leaf of all varienties, almost
paralled to those of leaf water potential, thus maintaining the
turgor level, thus because, the concentration of the major solutes
of expanded leaf of all varieties, also exhibited a significant
diurnal variations, and weren''t much changed by mild stress. The
only change cuased by mild stress was starch/sucrose partitining
ratio.
2. The photosynthetic rate, leaf conductance and leaf relative water
content of each variety decreased with leaf water potential; and
varied with varieties. The physiological responses could be used
as indicators for selecting drought resistance.
3. Under moderate stress (-1.2 - -1.5 Mpa), the osmotic potential of
expanded leaf of all varieties showed adjustable in various degree.
The more drought-resitant strains, like maize TN11 and barley CB15,
have much more solutes than those non-resisteant strains, like maize
TNG351 and barley CH2. Therefore, osmoregulation can be maintaned
and allowed to continue expansion growth under growth-inhibiting
drought condition as well.
4. Leaf elongation is very sensitive to water shortage, and was
inhibted under mild stress; For maize TN11, TNG351; barley CH2,
CB15, leaf elongation ceased when predawn declined to -1.3 Mpa,
-1.1 Mpa; -1.1 Mpa, -1.45 Mpa. Since the selongation of leaves
os ,pre semsotove tp tje water supply, it gave a significant
influence to the yield capacity, and it is so easily to dectate, so
the response of LER (leaf elongation rate) to water stress, has
become a useful indicator for screaring drought-resistant plants.
5. The Li+, Na+, K+ contents of the elongation leaves kept constant
under the water stress condition. The orgainic compounds were
accumulated significantly at early drought stage, and give a
considerable influence to the osmotic adjustment. The earliest
response to water deficits was the accumulation of soluble sugar
content, then, the free amino acid. All these material were
involved in osmotic adjustment. When the condition of water supply
get worse, the extension growth of leaves had almost creased and
metabolism of sugar and nitrogen compounds were also influenced.
This showed that the necessity of growth is much related with the
metabolism of feed back control.
6. As for the restoration of rewatering after water shortage, it give
a corelation with crop varieties. The result showed, when the
variety gave more drought-resistance, the leaves related with yield
and physiological reactions, restored more healthy and stronger.
7. From the soil-sand culture, the result showed that the shoot growth
of the plant under the water stress condition was reduced more than
the root growth. This indicated that root-shoot ratio are increased
by water stress. On the other hand, the cell wall extensibility
were also decreased gradually after a long term of drought.
Therefore, water deficits could also changed the leaf biophysical
trait.
8. The important factors which effects the yield components are the
time of water shortage and the degree of water stress. If the
flower buds of plants were initaited under various water stress
condition, then the grains per spike and panicle weight would be
decreased, However, the plant height and panicle length were not
influenad, consequently, the water are more short, the yield are
more lower. When the period of plant internode elongation was under
water shortage condition, the plant height was decreased
significantly, the grains per spike and the weight of per 100 grains
were also decreased. During the flowering stage, the water stress
would influence the yield of grains per spike, the flowering date
both barley and maize were delayed as well. In the milk-riping
stage, the weight of per 100 graing would be effected by water
stress, the seed filling period was also getting shorter.
水分為影響植物生長重要環境因子之一,但臺灣地理環境及氣象條件特殊,因此作物
仍常有缺水的危機,因此了解植物對缺水的反應、抗旱生理、缺水與產量構成因子之
關係,為推行稻田轉作之基礎工作之一.
本研究以生理學及生物化學為基礎,針對玉米、大麥進行下列四項探討:
1.輕中度缺水時,展開葉之生長、生理現象.
2.正展開葉片,於缺水、復水狀況下,其生長、容質消長情形及其所代表之意義.
3.利用盆栽砂土混合試驗,探討缺水時根/芽比,及葉面積變化,並進一步探討限制
伸長的可能原因.
4.探討缺水對產量構成因素之影響.
結果摘要如下:
1.供試材料玉米、大麥之對照植株及輕中度缺水植株(-0.8∼-1.5Mpa ),其展開葉
之葉片水分潛勢、滲透潛勢、均有日變化情形,且滲透潛勢日變化曲線,幾乎平行於
葉片水分潛勢日變化曲線線,而使葉片之膨至維持正值;此乃因葉內溶質含量亦有日
變化情形;輕中度缺水時,葉內溶質含量變化,未受嚴重影響,僅澱粉/蔗糖分配率
受影響.
2.各供試品種之淨光合率及葉片導度、葉片水分含量,均隨葉片水分潛勢下降而減小
,且具品種間差異性存在,此差異性與品種之耐旱性有關;故缺水時,光合成機能之
持續力、及葉片水分含量,均可當耐旱性之重要指標,
3.中度缺水(-1.2∼-1.5Mpa )時,各供試品種之展開葉均表現滲透調節象,且愈抗
旱之品種如玉米TN11、大麥CB15其葉內溶質累積量大於較不抗旱者,如玉米TNG351、
大麥CH2 ,因之較能發揮滲透調節作用,適當延緩缺水對葉片生長之影響.
4.葉片伸長速率,對植株水分狀況非常敏感.輕中度缺水時,葉片伸長已受抑制;玉
米TNG351;大麥CH2、CB15 分別於黎明前葉片水分潛勢(predawn ψ ) 為-1.3Mpa,
-1.1Mpa;-1.1Mpa、-1.45Mpa時停止生長,由於葉片伸長對水分具高敏感性在加上
其測量容易及對產量具深遠影響,因此葉片伸長對缺水反應,為選擇抗旱之有效方法.
5.缺水時,各供試品種之正伸長葉,除
(圖表省略)
外,有機溶質累積現象明顯;且各種有機溶質對滲透調節貢獻各異,缺水初期,主要
由可溶性醣類,負責調節滲透潛勢,而後有游離胺基酸參與.但若缺水狀況持續惡化
,則正伸長葉停止伸長,同時醣類代謝、氮素代謝亦受影響,因此生長需求與回饋性
抑制的代謝活動間有密切關係存在.
6.缺水後予以復水,其恢復能力,有品種間差異性存在.但愈抗旱之品種,復水後,
無論在生理反應上或與產量息息相關之葉面積上其恢復能力均較強.
7.盆栽砂土混合試驗顯示,斷水處理後,缺水植株,芽的生長要比根的生長易受缺水
影響,而導至根/芽比,產生顯著變化.且具品種差異性存在.除此而外,各供試品
種之葉片塑性變形值,亦因斷水處理而日益減少.因此很明顯地,缺水亦影響葉片之
生化物理特性.
8.缺水程度及缺水時期之不同,對產量及產量構成因子之影響各異.供試品種於幼穗
分化期,予以不同程度缺水時,產量構成因素中,以每穗粒數,穗重易受缺水影響.
而株高、穗長受缺水影響較小;缺水程度愈嚴重,產量降低愈明顯.節間快速伸長期
缺水,導致供試植株變矮,每穗粒數、百粒重均略為減少.開花期缺水,嚴重減少每
穗粒數,亦使玉米開花期至雌穗抽絲期、大麥之開花期延長.乳熟期缺水,常導致百
粒重減輕,並使各品種之榖粒充實期縮短.
URI: http://hdl.handle.net/11455/21458
Appears in Collections:生命科學系所

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