Comprehensive Evaluation Of Drought Resistance Of Hippophae Rhamnoides L. Germplasm Resource

In order to select the drought resistant germplasm resource of Hippophae rhamnoides L.in Inner Mongolia,we did a study with 1-year-old seedlings of 10 provenances of Hippophae rhamnoides L.from the drought tolerance of growth characteristics,anatomical structure,physiological and biochemical characteristics.At last,have a comprehensive evaluation of drought resistance of different germplasm resource by the method of principal component analysis and membership function.The main results are as follows:(1)The peak-growth period of Hippophae rhamnoides L.is on June to August,and it stopped growing in October.The significant difference was found in the growth of different provenance.Guyang provenance has the best growth,and followed by Laobaigou provenance and Boketu provenance.The worst growth is Nileke and Zhuolu provenance.From the index about plant morphology,Laobaigou provenance has not only the smallest ratio of height to diameter,but also the largest ratio of root to shoot and smaller leaf area.And it has one of the longest tap roots than other provenances.Integrated these indicators,and we can find that Laobaigou provenance has the advantage of drought resistant in the growth.(2)The soluble sugar content,the soluble protein content,the proline content,POD activity,SOD activity and MDA content of 10 provenances are significantly different.The correlation analysis shows that there has a positive correlation between seedling height and ground diameter and the osmotic adjustment substances.The SOD activity is higher in the leaves,and the content of MDA was lower,which was the physiological characteristic of Hippophae rhamnoides L.(3)The photosynthetic characteristics and chlorophyll fluorescence parameters of 10 provenances are significantly different.Correlation analysis shows that there is a positive correlation between seedling height and ground diameter and photosynthetic fluorescence parameters.The Etuoke provenance has the highest net photosynthetic rate,followed by Guyang provenance,and the Qinan provenance is the lowest.There is a positive correlation between net photosynthetic rate,transpiration rate and stomatal conductance.Transpiration rate,stomatal conductance and intercellular CO2 concentration are moderately positively correlated.The stomatal conductance,intercellular CO2 concentration and water use efficiency showed a highly significant negative correlation.And during this study,the main factor of photosynthesis inhibition is stomatal limitation.(4)The morphological and anatomical structures of the three parts of the leaves,stems and roots of Hippophae rhamnoides L.are characterized by the structure of the plants,such as the big leaf thickness,palisade tissue,the large ratio of palisade tissue and spongy,and leaf tissue structure tightness;the large ratio of stem pith,and strong vascular bundles surrounding the stem pith,cortical thickness;column root in large proportion,leading organization developed,cortex proportion is small,peripheral thick skinned,cork multi layer cells,compact arrangement.(5)Comprehensive the physiological and growth index,Guyang,Laobaigou and Etuoke provenances have stronger drought resistance,and Zhuolu and Qinan provenances' drought resistance are weak.Integrated the morphology index,we can find that the Laoaigou,Longfenggou,and Tenihe provenances' sdrought resistance are stronger than other provenances.Boketu provenance has the worst drought resistance.According to physiology,growth and morphological results,the source for the strongest drought resistance is the Laobaigou provenance,and the drought resistance of the Zhuolu is the worst kind of source.The mechanism of drought resistance are drought avoidance and drought tolerance in the area of Etuoke of Hippophae rhamnoides L.