Shading, High Temperature Stress On Six Herbs' Growth And Plant Physiology

In China, we all know one of the three most hottest country is Chongqing, extreme summer temperatures can even reach to 43.8℃. Plants have two ways to cope with high temperatures, one is use the cultivation of plant facilities to reduce the degree of heat injury, the second way is filter plant species which can withstand high temperature. In this paper, six kinds of herbal plants was used to explore those physiological changes under differrent shading. and compare the two varieties of lavender's physiological changes during high temperature stress in order to select some herbs to promote in Chongqing.Through the treatment with shading and high temperature stress about six herbs, we can get the following results:(1) Six herbs'height increment, internode, stem diameter increment, leaf area, leaf water content increased with inceresed shading; specific leaf weight, chlorophyll a/b, soluble sugar degree of concentration decreased with increasing shade; daily average net photosynthetic rate increases with increasing shading,when it reached a maximum value it decreased; POD activity in general show as decreased with increasing shading, when achieve the minimum it will rebound, POD activity showed a "V" shape. Shading had different effects on the protein, MDA, proline, CAT, SOD,overall,the various was different.(2)Through Principal component analysis and Membership function of the six herbs'relative value of related indicators,we got those resoult of Shade-tolerant capability by six herbs as follow:Melissa officinalis,Salvia officinalis,Cymbopogon Citratus,Plectranthus ecklonii cv.'Mona Lavender',Rosmarinus officinalis,Lavandula[Munstead].the resoult was consistent with the resoult observed in cultivasion. Noting that the result is feasible.(3)Through Quantitative description with six herbs under different shading, Initially determined the Appropriate shading to each herbs, it also Provide a scientific basis to Configurae plant science properly. The result is:light has less affect in Melissa officinalis, Salvia officinalis,they have high value in Garden promotion. Cymbopogon Citratus grow best in full sunlight; Rosmarinus officinalis, Plectranthus ecklonii cv.'Mona Lavender', Lavandula[Munstead] grow best under 50% shading.. From this, in view of the high temperature in Chongqing, Chongqing open field can be planted in the vanilla plant types:Melissa officinalis,Salvia officinalis,Cymbopogon Citratus,if give some Moderate shade, Plectranthus ecklonii cv.'Mona Lavender',Rosmarinus officinalis,Lavandula[Munstead] can also be used.(4) sustained high temperature makes Lavandula [Munstead] and lavender stoechas physiological changed, specifically as follows:chlorophyll content, soluble protein decreased; soluble sugar concentration, proline, malondialdehyde upward trend; POD, CAT, SOD and then decreased.lavender stoechas had smaller increase than Lavandula. [Munstead]. Lavandula [Munstead] have Stronger resistance than lavender stoechas. This is consistent with the cultivation.