| Heritiera littoralis Dryand., Sterculiaceae, an amphibious tree species both incoastal waters and lands, can be used as an excellent sheltering forestation tree species,and it is scientifically very significant to study its provenance biodiversity. The seedsof three provenances of Heritiera littoralis, located in Yanzao, Shenzhen; Xiangkeng,Shanwei and Jilong Mount, Zhanjiang were collected as experimental materials forthe provenance trial to study the growth differences and its genetic variation andphotosynthetic characteristics of the three provenance seedlings. Using pot-plantingexperiment method with salt stress treatments for Heritiera littoralis seedlings, thispaper studied the seedling’s physiological and biochemical characteristics, leaf tissueanatomy, and proteomics analysis to explore the mechanism of their salt tolerance insimulating field salt stress environments so as to provide the theoretical and technicalsupports for promotion of introduction and afforestation of Heritiera littoralis. Theresults were as follow:1. There were big differences of hundred-seed weight and germinating rate ofHeritiera littoralis seeds between different provenances, the hundred-seed weightwith variation of686.9～1028.7g and the germinating rate with variation of73～95%respectively. There were significant differences of seedlings height, the numberof leaves, diameter at the base and biomass of different organs between threeprovenances of Heritiera littoralis seedlings in the experiment. The results showedthat，the broad heritability of the biomass of different provenances of Heritieralittoralis seedlings is greater than0.985and the differences are mainly controlled bygenetic factors.2. The results showed that there were no obvious differences of chlorophyll a,chlorophyll b and chlorophyll total content of different provenances of Heritieralittoralis seedlings. But there were a little big differences in net photosynthetic rate(Pn), transpiration rate (Tr)，stomatal conductance (Co), the results reflected the differences of photosynthesis ability between the three provenances and the Heritieralittoralis seedlings of Yanzao of Shenzhen provenance had higher photosyntheticcapacity.3With the increasing concentration of salt stress, the relative height incrementand relative stem increment of Heritiera littoralis seedlings of Yanzao of Shenzhenprovenance were on declining trend; the relative height increment of Heritieralittoralis seedlings Jilong Mt. of Zhanjing and Xiangkeng of Shanwei provenanceswere on declining trend with increasing salt treatment, but its relative stem incrementwere increasing first and then descending. With the increasing salinity, theChlorophyll content of the three provenances of Heritiera littoralis seedlingsdecreased, the SP content showed a downward trend after an initial increase, MDAand Pro content were increasing, SOD activity decreased. This paper made thecomprehensive assessment of seedling salt tolerance of the three provenances ofHeritiera littoralis seedlings combined membership function method, the resultsshowed that the Heritiera littoralis seedlings of Jilong Mt. of Zhanjing was thestrongest salt resistance, the weakest salt resistance is the Yanzao of Shenzhenprovenance.4. The results showed that, compared with the control group, under moderatesalinity of10g/kg (NaCl/matrix) treatment, the arrangement of the palisade tissue ofthe leaf was more closely distributed with a large number of clusters of calciumoxalate appeared, this showed it have a a certain salt tolerance. However, with highsalinity of19g/kg (NaCl/matrix), some of the cells were broken with a large numberof irregular arrangements of glandular hairs on the hypodermis.5. Extracting the total protein of the leaves of Heritiera littoralis seedlings withphenol extraction, by isoelectric focusing (24cm, pH4-7glues tape,52KVh) and12.5%SDS-PAGE for separation, obtain two-dimensional electrophoresis by silverdye dyeing and scanning. The number of protein point in each figure was more than1677, mainly distributed in pH4-7and the molecular weight of17kDa-170kDa. Theresults indicated108protein spots showed significant and reproducible changes aftersalinity (10g/kg) treatment, including38down-regulated,37up-regulated,24newly-appeared,9disappeared protein spots. While there were137protein spots showedsignificant and reproducible changes after salinity (19g/kg) treatment, including56down-regulated,52up-regulated,24newly-appeared,5disappeared protein spots.3successfully identified proteins were assigned as isoflavone reductase homolog, chlorophyII a-b binding protein of LHCII, and superoxide dismutase of Cu, Zn. |
