“七五”期间我国农业生物技术发展的回顾

一、概况我国自第七个国民经济五年发展计划以来,作为增强农业发展后劲的重要战略措施,发展农业生物技术受到了广泛重视,在中央及有关部委领导关心下,农业生物技术被正式列入国家科技发展计划,在基础设施建设、科研经费投入、人才队伍建设等方面得到了较大支持. 我国农业生物技术研究起步于七十年代中期,但是由国家有计划地组织研究是在“七五”期间开始的.目前的研究领域主要有: 1.生物技术改良作物遗传性状利用花药培养技术培育作物新品种;植物细胞培养和融合技术以及体细胞无性系变异体离体筛选技术在培育作物优良新品种中的应用;应用基因工程技术定向转移优良目的基因,改良作物品种.还有蔬菜、花卉和果树等植物的快繁、脱毒等.     

芸苔属作物的原生质体培养和细胞融合

本文就70年代以来芸苔属作物的原生质体培养和细胞融合技术的研究进展及其应用前景作了综述,特别对通过细胞融合产生胞质杂种及其在芸苔属作物育种实践中的应用作了讨论。     

Moricandia与芸苔属植物亲缘关系的研究

Ｍｏｒｉｃａｎｄｉａ是十字花科中唯一的具Ｃ３Ｃ４植物的属。为向十字花科芸苔属（Ｂｒａｓｉｃａ）作物中转移Ｃ３Ｃ４等重要性状提供基本信息,从可交配性和ＲＦＬＰ指纹图谱两个角度研究了Ｍｏｒｉｃａｎｄｉａ与芸苔属作物间的亲缘关系。结果表明：Ｍｏｒｉｃａｎｄｉａ与芸苔属作物间的可交配性很低,仅从Ｍ．ａｒｖｅｎｓｉｓ×甘蓝型油菜的１０５枚培养子房中获得４个杂种苗。用２３个甘蓝型油菜核ＤＮＡ探针和４个甜菜线粒体ＤＮＡ探针检测了芸苔属作物和ＭｏｒｉｃａｎｄｉａＣ３Ｃ４植物间ＤＮＡ限制性内切酶位点多态性。Ｍｏｒｉｃａｎｄｉａ与芸苔属物种间的同源性很高,其中白菜型油菜与Ｍ．ｎｉｔｅｎｓ之间在核基因组上的相似性甚至大于它与同属的甘蓝型油菜间的相似性。ＭｏｒｉｃａｎｄｉａＣ３Ｃ４物种与芸苔属作物在核ＤＮＡ和细胞质ＤＮＡ间的高度同源性,揭示了通过有性杂交或原生质体融合及染色体间重组的途径向栽培种转移重要基因的可能性。     

高温预处理对大白菜游离小孢子培养的效果(简报)

自从Keller在甘蓝型油菜花药培养中首次用高温处理提高了花粉胚的诱导频率以来,该方法被广泛用于芸苔属不同作物的花药培养     

经遗传修饰生物体的研究进展及其释放后环境的影响

８０年代以来,以基因江程为代表的生物技术突飞猛进。转移不同性状的基因作物在美国被批准进入大田试验的有４０个以上的作物,包括小麦、玉米和水稻等４种谷类粮食作物,主要的纤维物棉花、蔬菜种类１０种以上,水果９种,其中还有油料作物,牧草和花卉等。到１９９６年６月已被批准进入市场的已有１８种,还有一批有待批准商业化。今年２月,美国农业部已第一次批准一种喂饲其它署期螨进入大田试验。第一个转基因线虫也正中申请向     

上海市农作物审定品种多样性与数据化共享

上海市于1984年实施农作物新品种审定制度,至2006年共审(认)定新品种464个,包括粮食作物153个、油料作物24个、纤维作物5个、蔬菜134个、瓜果85个、食用菌31个。本文分析了上海市审定品种的物种多样性和主要作物的性状变异,并以水稻为例分析了水稻审定品种的多样性及育种成就,探讨了在水稻产量提高过程中的产量构成因子的作用。介绍了上海市审定品种数据化共享系统及其应用方法。     

转基因生物技术的知识产权保护

转基因生物技术是现代农业生物技术的重要着力点,其自研发以来不断发展,已在多种作物上成功应用,且培育品种日趋多样化。转基因作物种植面积急剧增加,种植国家也逐年增多。目前转基因生物技术水平较高的国家,其知识产权保护水平也往往较高。而我国转基因植物、动物和其他微生物材料,无法通过我国现行的《专利法》、《植物新品种保护条例》获得有效保护,阻挠了转基因生物技术创新发展,更影响到整个国家的粮食安全和农业安全。     

转基因作物与环境保护

转基因作物与环境保护孟小雄编译随着生物技术的发展,转基因植物（工程物种）不断出现,然而在这些新品种的推广过程中,却受到各方面的限制,特别是环境保护部门。由此带来的烦恼也是生物技术专家所始料不及的。近期美国在推广抗溴甲腈棉花转基因品种受阻就是这样一个问...     

亚洲农业生物技术发展现状和前景(上)

1前言近年来,在现代生物技术的推动下,作物改良已取得巨大进展。基因组图和基因转移研究的突破,使科学家得以完成常规育种难以实现或不可能实现的作物改良。第一批问世的基因改造或转基因(GM)作物,包括了具有诸如耐虫和/或耐除草剂等重要性状(所谓输入性状)的栽培植物。现今,这些第一代GM作物,正在向发达国家和发展中国家的农民显示其价值。嗣后,又有另一些作物例如Fla vr Savr番茄,经过基因改造,改善了其营养品质或延长了其货架期(有效保存期)(输出性状)。一些富含例如油酸、月桂酸和亚油酸的优质油料作物,已在经过批准后投入市场。现今…     

植物基因工程的研究及发展趋势(书面)

生物技术是10多年来迅速发展起来的高技术、新技术,具有十分明显的社会效益和经济效益。在所有的生物技术领域中,农业生物技术、特别是有关作物生物技术的研究和发展被认为是最有现实意义的技术之一,将在下一世纪出现的“绿色革命”中发挥巨大的作用。农业生物技术研究的内容有植物基因的操作,植物细胞和植物组织的培养,转基因植物和转基因鱼类、家畜家禽的获得等。农作物生物技术方面主要研究方向是提高蛋白质含量,改良氨基酸组成,提高作物抗逆境、细菌、真菌和病毒病以及抗虫     

Isolation of genomic DNA from defatted oil seed residue of rapeseed (Brassica napus)

A simple protocol for obtaining pure, restrictable and amplifiable megabase genomic DNA from oil-free seed residue of Brassica napus, an important oil seed plant, has been developed. Oil from the dry seeds was completely recovered in an organic solvent and quantified gravimetrically followed by processing of the residual biomass (defatted seed residue) for genomic DNA isolation. The isolated DNA can be cut by a range of restriction enzymes. The method enables simultaneous isolation and recovery of lipids and genomic DNA from the same test sample, thus allowing two independent analyses from a single sample. Multiple micro-scale oil extraction from the commercial seeds gave approximately 39% oil, which is close to the usual oil recovery from standard oil seed. Most of the amplified fragments were scored in the range of 2.5 to 0.5 kb, best suited for scoring as molecular diagnostics.     

Suppression of the SUGAR‐DEPENDENT1 triacylglycerol lipase family during seed development enhances oil yield in oilseed rape (Brassica napus L.)

Increasing the productivity of oilseed crops is an important challenge for plant breeders and biotechnologists. To date, attempts to increase oil production in seeds via metabolic pathway engineering have focused on boosting synthetic capacity. However, in the tissues of many organisms, it is well established that oil levels are determined by both anabolism and catabolism. Indeed, the oil content of rapeseed (Brassica napus L.) has been reported to decline by approximately 10% in the final stage of development, as the seeds desiccate. Here, we show that RNAi suppression of the SUGAR‐DEPENDENT1 triacylglycerol lipase gene family during seed development results in up to an 8% gain in oil yield on either a seed, plant or unit area basis in the greenhouse, with very little adverse impact on seed vigour. Suppression of lipolysis could therefore constitute a new method for enhancing oil yield in oilseed crops.     

Oil content of Arabidopsis seeds: the influence of seed anatomy, light and plant-to-plant variation

Arabidopsis thaliana is frequently used as a model for the study of oilseed biology and metabolism. However, the very small seeds of Arabidopsis can complicate analysis of their oil content and influence the application of results to larger-seeded plants. Here, we describe how seed anatomy, light, and plant-to-plant variation influence the content and measurement of oil in Arabidopsis seeds. The anatomy of Arabidopsis and Brassica napus seeds were compared and the distribution of mass, oil and the fatty acid composition of different seed parts were determined. In Brassica, 90% of the seed oil resides in the cotyledons that contribute 74% of seed mass. By contrast, the values for Arabidopsis are 60% and 45%, respectively, with a higher fraction of the oil deposited in the radicle, hypocotyl, endosperm and seed coat. Growth of Arabidopsis plants with 600 micromol m(-2) s(-1) light resulted in a two-fold higher seed yield, a 40% increase in mass per seed and a 60% increase in oil per seed compared to growth at 100 micromol m(-2) s(-1). Factors that influence the analysis of oil content were evaluated. Intact-seed transmethylation followed by gas chromatography (GC) analysis provided reproducible analysis of Arabidopsis seed oil. However, plant-to-plant variation in oil content is large and we analyzed how this influences the ability to detect statistically valid changes in oil between different genotypes. These observations establish a reference data set on the fatty acid composition and distribution of mass and oil between tissues of Arabidopsis seeds that should help to predict the applicability of results obtained with Arabidopsis to other oilseeds.     

Antisense suppression of type 1 diacylglycerol acyltransferase adversely affects plant development in Brassica napus

Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-coenzyme A (CoA) dependent acylation of sn -1,2-diacylglycerol to form triacylglycerol in the terminal step of seed oil formation. Previous work has suggested that the level of DGAT activity may have a substantial effect on the flow of carbon into triacylglycerol, implying that the enzyme may represent a promising target for seed oil modification through biotechnological approaches. In the current study, Brassica napus DH12075 was transformed with an antisense type 1 DGAT construct, resulting in a reduction in DGAT1 gene expression, total DGAT activity and seed oil content. In addition, reduced seed yield and germination rates were observed along with severe developmental abnormalities. These data suggest that in addition to its critical role in seed oil formation, DGAT1 enzyme may also be important for normal seed development in B. napus , although the underlying mechanism(s) remain to be determined.     

Bottlenecks in erucic acid accumulation in genetically engineered ultrahigh erucic acid Crambe abyssinica

Erucic acid is a valuable industrial fatty acid with many applications. The main producers of this acid are today high erucic rapeseed (Brassica napus) and mustard (Brassica juncea), which have 45%–50% of erucic acid in their seed oils. Crambe abyssinica is an alternative promising producer of this acid as it has 55%–60% of erucic acid in its oil. Through genetic modification (GM) of three genes, we have previously increased the level of erucic acid to 71% (68 mol%) in Crambe seed oil. In this study, we further investigated different aspects of oil biosynthesis in the developing GM Crambe seeds in comparison with wild‐type (Wt) Crambe, rapeseed and safflower (Carthamus tinctorius). We show that Crambe seeds have very low phosphatidylcholine‐diacylglycerol interconversion, suggesting it to be the main reason why erucic acid is limited in the membrane lipids during oil biosynthesis. We further show that GM Crambe seeds have slower seed development than Wt, accompanied by slower oil accumulation during the first 20 days after flowering (DAF). Despite low accumulation of erucic acid during early stages of GM seed development, nearly 86 mol% of all fatty acids accumulated between 27 and 50 DAF was erucic acid, when 40% of the total oil is laid down. Likely bottlenecks in the accumulation of erucic acid during early stages of GM Crambe seed development are discussed.     

Small RNA profiling in two Brassica napus cultivars identifies microRNAs with oil production- and development-correlated expression and new small RNA classes

MicroRNAs (miRNAs) and small interfering RNAs are important regulators of plant development and seed formation, yet their population and abundance in the oil crop Brassica napus are still not well understood, especially at different developmental stages and among cultivars with varied seed oil contents. Here, we systematically analyzed the small RNA expression profiles of Brassica napus seeds at early embryonic developmental stages in high-oil-content and low-oil-content B. napus cultivars, both cultured in two environments. A total of 50 conserved miRNAs and 9 new miRNAs were identified, together with some new miRNA targets. Expression analysis revealed some miRNAs with varied expression levels in different seed oil content cultivars or at different embryonic developmental stages. A large number of 23-nucleotide small RNAs with specific nucleotide composition preferences were also identified, which may present new classes of functional small RNAs.     

播种期和种植密度对冬油菜籽粒产量和含油率的影响

通过田间试验研究了播种期和种植密度对冬油菜籽粒产量和含油率的影响.结果表明： 播种期主要影响分枝花序籽粒产量,而种植密度不仅影响分枝花序籽粒产量,还对主花序籽粒产量产生一定影响;籽粒含油率不受播种期的影响.主花序籽粒产量占单株籽粒产量的比例随种植密度的增加而升高,主花序籽粒含油率比分枝花序高约1%,因此小区籽粒含油率随种植密度的增加显著升高.研究区冬油菜播种期不能晚于10月中旬,10月下旬播种会显著降低籽粒产量;种植密度在每平方米36～48株可以提高冬油菜籽粒产量和含油率.     

Artificial synthesis of Brassica juncea Coss

Commonly cultivated mustard, Brassica juncea Coss, is an amphidiploid having in its genetic system the full 20-chromosome A genome (Brassica campestris) and the 16-chromosome B genome (Brassica nigra). Considerable natural variability exists under the A genome. These variations have been exploited for the artificial synthesis of B. juncea in order to breed improved mustard. The different combinations were studied both in their F₁'s and advanced amphidiploid generations in respect of their morphology, meiotic behaviour and fertility. Amphidiploids from leafy and rapiferous groups were generally bushy having arboreal habit. Some combinations from the leafy group result in types with luxuriant vegetative growth and can be used for fodder purposes. The amphiploids of ssp. rapifera did not give a swollen and enlarged root like the mother parent. None of the combinations from these two groups was promising in respect of oil and seed yield. Amphidiploids from the oleiferous group were both high seed and oil yielders and thus provide evidence that it formed one of the constituent parental species in the formation of oil yielding B. juncea.     

Lipids in Cruciferae

The effect of nitrogen, phosphorus and potassium nutrition on average seed weight, oil content and fatty acid composition of rape seed (Brassica napus) grown in soil-free culture has been studied. Nitrogen effected an increase in seed weight and a decrease in oil content, while the average amount of oil per seed remained constant. A small, but highly significant, decrease in palmitic and eicosenoic acid content, a significant decrease in oleic acid and a highly significant increase in erucic acid content were observed. This suggests that a decrease in the extent of elongation of oleic acid to erucic acid occurs in seeds developing on plants with sub-optimal levels of nitrogen nutrition. Phosphorus and potassium had very limited effects on fatty acid composition. Significant differences were found only in oleic acid content for phosphorus alone, the nitrogen-phosphorus interaction and the phosphorus-potassium interaction. The effect of various levels of sulfate at optimal levels for nitrogen, phosphorus and potassium, was studied in a separate experiment. Seed from sulfur-starved plants had decreased oil content; oleic acid percentages were increased and erucic acid percentages decreased. Excessive amounts of sulfate had no effect on fatty acid composition.     

Characterization of genes expressed during the development ofBrassica napus pollen

Summary The study of the formation of pollen in plants has been the focus of extensive morphologic and cytologic observations. This complex developmental process requires the coordinated activity of both gametophytic and sporophytic tissues. The events that occur during microspore development represent a carefully orchestrated program of physiologic, biochemical, and genetic activities. Genes expressed specifically in pollen or in sporophytic tissues that support pollen development have only recently been identified and desribed. In the present paper we describe several genes expressed during pollen development in the important oil seed speciesBrassica napus (oil seed rape/canola). The characterization of three gene families expressed during microspore development is reviewed which provides a basis for comparison with other genes expressed during pollen maturation. The, potential value of these genes for the development of novel plant breeding strategies and hybrid seed production is discussed. Presented in the Session-In-Depth In vitro, Gametophyte Biology at the 1991 World Congress on Cell and Tissue Culture held in Anaheim, CA, June 16–20, 1991.