Cauchy判别法的核心和难点是选择合适的p-积分作为比较对象.当被积函数的结构较复杂或抽象时,更难确定合适的p-积分.鉴于此,文章提出了Cauchy试验法,旨在快速准确地找到合适的p-积分,进而判断原积分的敛散性.>>详细Cauchy判别法的核心和难点是选择合适的p-积分作为比较对象.当被积函数的结构较复杂或抽象时,更难确定合适的p-积分.鉴于此,文章提出了Cauchy试验法,旨在快速准确地找到合适的p-积分,进而判断原积分的敛散性.

Three new tmm mutants were isolated and showed differential phenotypes from tmm - 1 , and TMM overexpression led to abnormal leaf trichomes.

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SDD1是气孔发育过程中的关键调控基因,编码一个类枯草杆菌(Bacillus subtilis)蛋白酶的丝氨酸蛋白酶.从EMS诱变的拟南芥(Arabidopsis thaliana)中筛选到2株类似sdd1-1的气孔密度突变体,即e281和g204.其气孔密度和指数均比野生型增加约1.5倍.气孔成簇.遗传分析和基因测序证实它们是2个不同的SDD1新等位基因,其突变分别导致了底物结合位点N区域和催化三联体之一--S区域的氨基酸变化,分别为S变成T及S变为F.形态学和生理学研究表明,SDD1基因不同位点发生突变可导致不同的生物学效应;而且SDD1等位基因间存在拮抗作用,其可能属于基因转应作用中的负效应.

Stomata are composed of two highly specialized guard cells,and serve as the major conduits for CO_2 and H_2O exchange between plants and the atmosphere.In Arabidopsis,stomatal development is not only initiated in some dispersed stem cells which undergo asymmetric divisions,but also a series of cell fate specialization events,and this process is regulated by cell-cell signals so that the newly formed stomata can maintain"One-cell spacing pattern"with the existing stomata or precursors.EPF1 may be a positional signal produced by stomatal precursors to regulate behavior of nearby cells.TMM-ER-family receptor complex and a MAPK signaling cascade, served as the negative regulators,orient the proper plane of asymmetric division during stomatal development and restrict stomatal differentiation.But positive regulators,bHLH transcription factor and MYB proteins,mainly control cell fate transitions in stomatal lineage.

In recent years,many genes in biosynthesis of long-chain polyunsaturated fatty acids(LCPUFAs) have been cloned and identified,and their biosynthetic mechanism has been elucidated.However,most higher plants don't produce LCPUFAs which have been playing important roles in human health.This review covered the latest advances on LCPUFAs biosynthesis in higher plants by genetic engineering,and discussed the current problems in genetic improvement and some feasible solutions to solve these problems.

The study of heavy ion beams as a new irradiation resource on seeds of linseed (Linum usitatissmum L.) was reported. After irradiated by 12C 6+ heavy ions (with irradiation dose: 6×108 cm-2,1.8×109 cm-2 and 3.6×109 cm-2 respectively),the biological characters,agricultural traits,pollens and polymorphic DNA of sample was studied in Linum usitatissmum L.. The results showed that 6×108 cm-2 of 12C 6+ could promote the linseed germination rate,plant height and pollen viability. The 1000-seed weight and the oil content of seed irradiated by 12C6+ heavy ions was increased with augment of irradiation dose respectively. It has been found that 3.6×109 cm-2 is the most effective dose for increment both of seed weight and oil content with 16.5% and 19.9%,respectively. Cytological observation re-veals that the highest dose (3.6×109 cm-2) can also induce alteration of pollen shape of linseed. Furthermore,RAPD(Randomly amplified polymorphic DNAs) analysis shows that 99 DNA fragments are amplificated by 14 primers and the polymorphic ratio is 52.5%.

Crops of Brassica napus L., Linum usitatissmum L., Allium fistulosum L. and Lens culinaris Medic. were irradiated by 80 MeV/u 12C6+ ion beams with doses of 30, 90 and 180 Gy. The germination rates and heights of seedlings of M1 and M2 generation of these four plants were studied. The results indicated that germination rates and average heights of the B. napus and L. usitatissmum were improved by appropriate dose treatment, while great suppression was found in the irradiated groups of the A. fistulosum. As far as the L. Culinaris was concerned, little differences was observed on M1 germination rate, but the 90 Gy irradiation was favorable to growth of plant. The treatments with 30, 90 and 180 Gy were inferior to contrast one on M2 germination rate of the four species. Seedlings of M2 generation of the B. napus, L. sitatissmum and L. culinaris under 30 Gy grew better than the other groups, while the best performance of the A. fistulosum was shown by the control group.