Increased Storability of Haloxylon ammodendron Seeds in Ultra-drying Storage

梭梭 (HaloxylonammodendronBge .)的种子为短命种子 ,在自然状态下 ,种子的含水量为 8.5 % ,寿命约为 10个月。将梭梭种子含水量降至 2 .5 %和 1.4% ,其耐贮藏力增强。经过 5 0℃下 5d和 10d的人工加速老化后 ,超干种子表现出较强的抗老化能力。与对照相比 ,超干种子具有较高的萌发率、活力指数及较长的根 。

Study on Seed Vigor of Rice Photo-ThermoSensitive Genic Male Sterile(PTGMS) Line with Low Temperature Storage

To explore the change rule of seed vigor and seed application technology of rice PTGMS lines with low temperature storage,Zhun S,Y58S,Feng S and Guangzhan 63-4S stored in the seed bank with the temperature of 8-10 ℃ and with the relative humidity of 55% for different years were used as the materials to study the properties of seed vigor,growth and development in the field, etc. The re- sults showed that the germination potential, germination rate, germination index and vigor index of rice PTGMS lines seeds showed downward trends as the time of low temperature storage prolonged,and all of the germination rates of the seeds within five years were over 60%. The conductivity in the soaked solution of seeds was significantly increased with the prolonged low temperature storage time. Seedling rate,root length,white root number,base stem width and seedling dry weight of seeds showed downward trends as the time of low temperature storage prolonged. There was no significant difference between two integral seedling qualities of seeds within 4-6 years in low temperature storage. Compared with the germination rate of low temperature storage seeds soaking for 6,12 and 24 h,the appropriate soak time of long time low temperature storage or low vigor seeds was 12 h. A serious natural aging phenomenon occurred in low temperature storage seeds after out of the storage. The germination rate of seeds placed under natural condition for 50 d decreased obviously. The duration from seeding to heading of Zhun S,Y58S and Feng S shortened as the time of low temperature storage prolonged, while the vari- ation of panicle duration of all PTGMS lines was not obvious. In conclusion, rice PTGMS line seeds with low temperature storage in 5 years could still be used nor- mally. However.seeds after low temperature storage should be sowed as soon as possible, and the soaking time of low vigor seeds should be shortened,and the possibility that the decreased duration from seeding to heading should also be con- sidered.

Effects of Nitric Oxide on the Germination of Wheat Seeds and Its Reactive Oxygen Species Metabolisms Under Osmotic Stress

Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).

Studies on Membrane Function and Sugar Components of Ultradried Seeds

The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicated that no significant differences in the activity of ATPase and the micro- viscosity of plasma membrane of ultradried (UD) seeds could be found as compared to the control seeds stored under -20 degreesC, although there was a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of UD seeds. This implied that ultradry seed storage could protect the integrity of the membrane, maintain its physiological function and improve the storability of seeds. The relationship between sugar and desiccation tolerance of UD seeds was analysed using the HPLC. The results showed that the ratio of reducing to nonreducing sugar was lower in UD seeds than that in control. The content of sucrose and stachyose in elm and Chinese cabbage UD seeds was related to their desiccation tolerance, while no stachyose was detected in corn (Zea mays L.) seeds. This could be one of the reasons for its sensitivity to desiccation.

球花石楠苗木培育实用技术

通过多年对球花石楠苗木培育的实际经验,总结了球花石楠采种及种子处理、苗床的选择处理、整地的注意事项、播种方法及应特别注意的事项、育苗期间的管理、病虫害防治等方面的苗木培育技术,以期为昆明地区球花石楠苗木生产应用提供理论依据及技术指导实用技术。

Processing Pisum sativum seed storage protein precursors in vitro

The profile of polypeptides separated by SDS-PAGE from seed of major crop species such as pea (Pisum sativum) is complex, resulting from cleavage (processing) of precursors expressed from multiple copies of genes encoding vicilin and legumin, the major storage globulins. Translation in vitro of mRNAs hybrid-selected from mid-maturation pea seed RNAs by denned vicilin and legumin cDNA clones provided precursor molecules that were cleaved in vitro by a cell-free protease extract obtained from similar stage seed; the derived polypep tides were of comparable sizes to those observed in vivo. The feasibility of transcribing mENA in vitro from a cDNA clone and cleavage in vitro of the derived translation products was established for a legumin clone, providing a method for determining polypeptide products of an expressed sequence. This approach will also be useful for characterising cleavage site requirements since modifications an readily be introduced at the DNA level.

Study of Peganum harmala Genetic Diversity Based on Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis （SDS-PAGE） Analysis

Syrian Rue （Peganum harmala L.） is grown in semi-arid conditions. Its origin is Central Asia and has several medicinal uses especially in seeds. Study of genetic diversity for this plant is important for researches in future. The electrophoresis of seed storage protein is a method to investigate SDS-PAGE and to classify plant varieties because these proteins are highly preserved. This study was conducted to determine the seed storage profiles of 20 Peganum harmala accessions that have been collected in some regions in lran. Extracted proteins were analyzed by Sodium dodecyl sulphate polyacrylamide gel electrophoresis （SDS-PAGE） as a biochemical marker. For this purpose, the samples were first crushed and seed protein was extracted by extraction buffer then total soluble proteins were resolved on 15% SDS polyacrylamide gels. The gels showed 20 bands that were high polymorphism among the accessions. The noticeable differences for example were observed in area with 38 KDa. The result of analysis showed that the accessions were classified in three groups （13, 3 and 4 accessions in the first, second and third groups respectively）.