| Semen Cassiae is the dried ripe seed of Cassia obtusifolia L. or Cassia tora L., whichbelongs to Leguminosae family. It has been commonly used to improve eyesight and reputedfor its medicinal values as a cathartic and diuretic and clear liver. Semen cassiae in ourcountry has a long history being used as medical, and its plant area is board. People often usecassia seed as a kind of tea. In recent years, products from semen cassiae have a steadilyincreasing demand in the fields of medicine, food and health care industry. However, with themodernization of traditional Chinese medicine, the habitat of wild Cassia obtusifolia wasseverely damaged, so that the wild distribution area in China continues to decline. Thecultivation of Cassia obtusifolia has a long history in China with wide plant area. But thereare still many problems: the germplasm resource is not clear, the cultivation management isnot standard, the processing techniques are not satisfied, which have restricted the increase ofthe yield and influence the quality of Cassia obtusifolia. Therefore, it is imperative to breednew semen cassiae strain with high yield, superior quality and strong resistance. In this study,the Cassia obtusifolia seeds are carried by “shenzhou8” spacecraft under the influence ofspace special environmental. For SP1and SP2generation, the plant biological characteristicssuch as plant height, across diameter, branch number had been strictly measured, thechlorophyll content in the leaves of SP1, SP2generation had been determined; the seedsharvest characteristics and the effective composition of SP1, SP2had been analyzed. Based onthe cultivation study for two consecutive years, this project has evaluated the effect of spaceflight on the plant on the plant biological characteristics, physiological indicators and theeffective composition content of SP1, SP2generation, in order to select excellent mutant strainwith high yield, superior quality, strong resistance of semen cassiae. The results are asfollowing:(1) After being carried by satellite, the plant height of plant of QC3, QC10, QC25, QC29,QC46, QC47in SP1generation, increased significantly compared with control, as well asacross diameter, branch number, yield of plant increased; while in the SP2generation, thegrowth characteristics remained superior to the control only in QC10, QC29, QC46mutantstrain. The QC3, QC29, QC46mutant strain have lost the advantage in the high yield; (2) Except for the significantly increasing in the conductivity of SP1generation, otherindicators had no significant difference compared with control; Despite the seed grains of SP2generation increased significantly, there was no significant alteration of the hard rate property,water content and other characteristics;(3) There was a significant rise in the leaf chlorophyll content of SP1generation plant,Superoxide dismutase (SOD) content was higher than control, but the content of Peroxidase(POD), Malondialdehyde (MDA) less than control, the seed soluble sugar content had notchanged significantly; while for SP2generation plant chlorophyll content was higher thancontrol, the antioxidant enzyme activity firstly increased and than decreased, and solublesugar content increased significantly;(4) The content of auranto-obtusin and chrysophanol, two effective components of seeds,only rised significantly in QC25, QC42from SP1generation; whereas the content ofauranto-obtusin and chrysophanol in SP2had not shown obvious changes, and content of allthe other samples were meet the requirement of Chinese Pharmacopoeia.The dry seeds of Cassia obtusifolia were carried by “ShenZhou8” satellite and sowedafter landing. The SP1, SP2generation seedling emergence, plant growth characteristics,chlorophyll content and effective components of SP1, SP2generation were analyzed. Aftertwo years’ study, some high-yield mutant strain numbered QC10, QC29, QC46were selected.The results indicate that space mutation breeding could provide new germplasm resources forCassia obtusifolia breeding, and provides a theoretical basis for further utilization of spacemutation to breed high-quality Cassia obtusifolia strains. As we know that breeding researchis a long and rigorous work, the further research need to apply some technologies ofmolecular biology to study mutant plant, and go on the research on SP3, SP4. |
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