可培养潜力

Pollen as the target for gene transfer is a potential plant transformation system which can avoid the problens of somaclonal variation and chimaera resulting from in vitro regeneration.

以花粉作为外源DNA的媒介，获得转基因植株是有潜力的遗传转化体系。它可避免离体培养过程中的遗传变异和转基因植株的嵌合现象。

B Of the six basic media MS, MS1/2 (half-strength of MS salts and vitamins), WPM, DKW, B5 and SH, MS1/2 was the most proper one to induce somatic embryos. Somatic embryos generally regenerated directly from excised zygotic cotyledons. PGRs combination affected somatic embryogenesis significantly. Medium with NAA 1mg/L, TDZ 0.05mg/L, IBA 2—10mg/L combined with BA 10mg/L, or IBA 10mg/L integrated with BA 0-2mg/L gave the highest induction rate. Excised zygotic hypocotyls had the strongest potential to produce callus. Callus induction was also affected significantly by media and PGRs. The proper callus induction condition was MS1/2 medium containing NAA 1mg/L, IBA 10mg/L, BA 2-5mg/L and TDZ 0.05mg/L. Harvest period affect somatic embryogenesis significantly. Zygotic embryo explants collected from the end of July to the middle of August had strong potential to generate somatic embryos, when endosperm finished solidification, different parts of the embryos were completely formed, the size of embryos occupied about 2/3 of the embryo sac. Provided with optimized conditions, direct somatic embryogenesis rate can attain to 33. 68%, and callus induction rate of hypocotyls was up to 90.7%. Cytological observation on megasporogenesis and zygotic embryogenesis of Manchurian ash showed that the ovary was twicarpellum, twilocular with two ovules each loculus. The ovule was tenuinucellar and anatropous, with one megasporcocyte. The development of embryo sac is of the Polygoum type.

体细胞胚胎发生研究的结果表明：(1)成熟过程中的合子胚是诱导水曲柳体细胞胚胎发生的最佳外植体材料；(2)在所试验到的MS、MS1/2（将MS的所有成分均减半）、WPM、DKW、B〓、SH等六种基本培养基中，MS1/2是最适合诱导水曲柳体细胞胚胎发生的基本培养基；(3)水曲柳的体细胞胚胎发生以直接发生为主，体细胞胚主要来自于从合子胚分离的完整子叶；(4)培养基中的激素组合对水曲柳的体细胞胚胎发生有显著影响，诱导直接体细胞胚发生较好的激素组合有NAA 1mg/L+IBA 2，5，10mg/L+BA 10mg/L+TDZ 0.05mg/L和NAA 1mg/L+IBA 10mg/L+BA 0，2mg/L+TDZ 0.05mg/L；(5)合子胚分离的下胚轴具有最强的愈伤组织诱导潜力，少数愈伤组织可以分化出体细胞胚；(6)愈伤组织的诱导也受培养基和激素配比的显著影响，最适宜诱导的培养条件为MS1/2+NAA 1mg/L+IBA 10mg/L+BA 2，5mg/L+TDZ0.05mg/L；(7)采种时间对体细胞胚胎发生有显著影响。7月末到8月中旬的合子胚具有较强的体细胞胚发生潜力，此时种子尚未成熟，胚乳已呈固态，种胚的各个部分已分化完全，种胚体积占胚腔的大约2/3；(8)在各自综合的最适条件下，完整子叶的体细胞胚诱导率可达33.68%，下胚轴的愈伤组织诱导率可达90.7%。

Under the guide of new course concept, our school promotes sustainable development of teachers and students and therefore has trained a number of students with stable learning basis, sharp-cut individual strengths, sufficient learning potentials and all-round development.

学校以新课程理念为指导，促进师生的多元、和谐、可持续发展，培养了一批又一批学习基础扎实、个性特长鲜明、学习潜力充足、发展和谐全面的学生。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。