Genetic Transformation of Brassica campestris L. ssp.pekinensis via Agrobacterium－ with Bt Gene

By means of Agrobacterium-mediated transformation, 43 kanamycin-resistant buds of Chinese cabbage were got. PCR, PCR-Southern blot and dot blot analysis were used to identify and characterize the putative transgenic plants. 26 plants had the predicted bands of the fragment of npt Ⅱ gene. Insect bioassays of 4 transformants showed that toxic protein had been translated and the translation levels were different among these transformants.     

Directional Breeding of An Oval-ecotype Male Sterile Line of Chinese Cabbage(Brassica campestris L. ssp. pekinensis)

[目的]探究大白菜定向转育卵圆生态型雄性不育系的方法。[方法]以大白菜核不育＂复等位基因遗传假说＂为理论依据,以甲型两用系‘AB12’为不育供体品系,以卵圆生态型可育品系‘06048’为待转育品系,采用杂交、回交、兄妹交和测交的方法,按照定向转育方案将核不育基因定向转育。[结果]各世代育性分离比率与理论相一致,成功育成了一种不育株率100%的具有‘06048’园艺性状的新核不育系,实现了核不育基因和园艺特性的同时转育。[结论]该研究成果验证此定向转育方案是可行的,进一步为基因型为 msms的其他园艺性状的大白菜定向转育提供理论基础,也可以推广应用到整个芸薹属其它经济作物中,极大的拓宽了优良核不育基因的实际应用范围。     

Identification of QTLs Related to Bolting in Brassica rapa ssp. pekinensis （syn. Brassica campestris ssp. pekinensis）

A genetic linkage map of Brassica rapa ssp. pekinensis was constructed with 186 AFLP （amplified fragment length polymorphism） markers by using a doubled-haploid （DH） population with 183 individuals. The individuals were derived from F1 which was developed by crossing a bolting resistant DH line Y-177-12 and an easy bolting DH line Y195-93a. AFLPs were generated by the use of restriction enzymes EcoR Ⅰ and Mse Ⅰ . The segregation of each marker and linkage was analyzed by using JoinMap version 3.0. Mapped markers were aligned in ten linkage groups which covered 887.8 cM with an average marker interval of 4.47 cM. Markers showing skewed segregation ratio were clustered in six LGs. Quantitative trait loci （QTL） were mapped for bolting resistance by using MAPQTL 4.0 package. Four QTLs explaining from 7.0 to 9.4% of the total variation were detected, all of them increase bolting resistance. These mapped QTLs could be used to develop a marker assisted selection programme for bolting resistance breeding.     

Cytological Observation of Microsporogenesis in Male-Sterile Lines of Chinese Pink （ Dianthus chinensis L.）

This study addressed the differences in microsporogenesis between male sterile and fertile lines of Chinese pink. The microsporogenesis processes of male sterile and fertile lines were histologically examined in squashed pollen grains and in paraffin embedded sections. A stable male-sterile line （H-37B） was obtained following six generations of inbreeding in a self-fertile line, followed by two generations of backcrossing. In the corresponding fertile line, development of the mature pollen grains was followed through the initiation of the sporogenous cell, microsporocyte formation, and the tetrad developmental period. In the male-sterile line, abortion of the developing pollen grains was observed to take place at various stages, namely, sporogenous cell growth, mother cell meiosis, and tetrad transformation to the uninuclear state. The pollen grains of the fertile line were spheroid, turgid, and viable. By contrast, the male-sterile line produced pollen that was irregular in shape, empty, and nonviable. The abortion of the microspore in the male-sterile line appeared to relate to abnormal growth of the tapetum layer.     

Exogenous Nitric Oxide Alleviated the Inhibition of Photosynthesis and Antioxidant Enzyme Activities in Iron-Deficient Chinese Cabbage （Brassica chinensis L.）

The effects of exogenous nitric oxide （NO） on plant growth, chlorophyll contents, photosynthetic and chlorophyll fluorescence parameters as well as lipid peroxidation and activities of antioxidant enzymes were investigated in Chinese cabbage plants exposed to iron （Fe） deficiency. Iron deficiency led to serious chlorosis in Chinese cabbage leaves, and resulted in significant decrease in plant growth, photosynthetic pigments, net photosynthetic rate, Fv/Fm, Ф ps Ⅱ and activities of antioxidant enzymes, and increase in lipid peroxidation. While treatment with SNP, a NO donor, it could revert the iron deficiency symptoms, increased photosynthetic rate as well as activities of antioxidant enzymes, and protected membrane from lipid peroxidation, as a result, the growth inhibition of Chinese cabbage by Fe deficiency was alleviated.     

Effects of Different Cadmium Levels on Active Oxygen Metabolism and H2O2-Scavenging System in Brassica campestris L. ssp. chinensis

The effects of different Cd (Cadmium) levels on generation of active oxygen speceies (AOS) and H2O2-scavenging system in the leaves of Brassica campestris L. ssp. chinensis were studied. The results showed that O2 generation rate, and H2O2 content were enhanced and malondialdehyde (MDA) content increased with the increase of Cd concentrations in the growth medium. The activities of ascorbate peroxidase (APX), dehydroascorbate reductase (DR) and glutathione reductase (GR) were promoted by the addition of Cd. Exposed to Cd also increased the contents of ascorbate (AsA) and glutathione (GSH) in the leaves.     

Monosomic Addition Lines of Flowering Chinese Cabbage (B. campestris L. ssp. chinensis var. parachinensis L. H. Bailey)-Chinese Kale (B. oleracea L. var. alboglabra L. H. Bailey)

Interspecific alien addition lines have played significant roles in gene mapping, intergenomic gene transfer and chromosomal homoeological identification between closely related species. Selection of alien addition lines was conducted by karyotype analysis and morphological observation with the reference of parents. Triploid interspecies hybrid (AAC, 2n=3x=29) was obtained from Brassica campestris ssp. chinensis var. parachinensis Qinglu 9601 (tetraploid, AAAA, 2n=4x=40)×B. oleracea vat. alboglabra Baihua 9705 (diploid, CC, 2n=2x=18) by immature hybrid embryo culture in vitro. Five different alien monosomic addition lines (AA C2, AA C3, AA C4, AA C6, AA C7) were obtained from the backcross progenies of AAC×AA. Each alien monosomic addition line has some specific morphological characters. It is feasible to obtain alien addition lines from the progenies of AAC×AA by karyotype analysis and morphological observation based on the reference of parents.     

广东菜心、芥蓝研究现状与展望

菜心和芥蓝是广东省重要的叶菜类蔬菜,具有种植面积大、复种指数高和市场需求量大的特点,其营养价值高,风味独特,已经成为人们日常饮食中必不可少的蔬菜种类。广东省是菜心和芥蓝秋冬季节的主产区。随着我国北方夏季种植区域的扩大,消费者对叶菜类蔬菜商品性和品质的需求提高,对现有品种的产量、适应性、抗性和风味物质含量等提出了新的要求。通过对种质资源的收集、保存和挖掘,广东省内各科研单位对菜心和芥蓝进行了大量的育种和分子生物学研究工作,促进了品种从常规种到杂交种的更替,也为未来分子育种打下了基础。而广东省菜心和芥蓝在实际生产中依然面临一些问题,需要从品种本身特性和挖掘优异种质资源上进行突破,利用现代生物技术与常规杂交育种技术相结合,提升品种在抗性、品质和适应性等方面的不足。综述了广东省菜心和芥蓝的研究历史、种质资源收集情况、分子生物学研究和产业发展现状,以期为广东省叶菜类蔬菜产业发展提供参考。     

菜薹-芥蓝单体异附加系n+1配子传递及两个二体异附加系的获得

【目的】研究菜薹-芥蓝单体异附加系n+1配子传递,为其在基因定位和遗传改良上的应用奠定基础。【方法】通过观察和统计各单体异附加系减数分裂后期Ⅱ10/10/11/11分离的PMCs,估算n+1配子的形成频率;通过鉴定回交子代植株的染色体数目,测定各单体异附加系n+1配子的传递率;从单体异附加系的自交子代中筛选二体异附加系。【结果】依据减数分裂后期Ⅱ10/10/11/11分离的PMCs比率估算,各单体异附加系n+1雄配子的形成频率在36.85%—45.15%;基于染色体数目鉴定,各单体异附加系n+1雄配子的传递率在7.14%—14.81%,雌配子在19.70%—36.51%;在一定范围内,n+1配子传递率与n+1配子形成频率、染色体大小、花粉量和花粉生活力没有显著的相关性;从自交子代中获得了两个不同的二体异附加系。【结论】菜薹-芥蓝各单体异附加系的额外染色体通过雌、雄配子均能进行传递,但传递率因不同的附加系而异;从单体异附加系的自交子代中可以分离出遗传性稳定的二体异附加系。     

大白菜-结球甘蓝5号二体异附加系的选育及鉴定

【目的】获得稳定遗传的大白菜-结球甘蓝二体异附加系。【方法】以大白菜-结球甘蓝5号单体异附加系为材料,对其自交后代进行细胞学及SSR鉴定。【结果】37株自交后代中2n=22植株的比率为10.81%,通过对4个2n=22的植株进行核型分析及SSR鉴定,确定其为大白菜-结球甘蓝5号二体异附加系。减数分裂观察发现,大白菜-结球甘蓝5号二体异附加系后期Ⅰ虽然出现染色体落后现象,但在后期Ⅱ中染色体的分裂方式以11-11-11-11为主,其比率为69.55%。【结论】获得了大白菜-结球甘蓝5号二体异附加系,其外源染色体与甘蓝07连锁群相对应;该二体异附加系减数分裂形成的四分体以附加1条的染色体为主(n=11),有较高的遗传稳定性。二体异附加系的获得为研究芸薹属A、C基因组的亲缘关系,以及向大白菜中导入结球甘蓝的优良基因具有重要意义。     

大白菜开花的温度反应特性研究

 以大白菜自交系03s205，03s206为试材，研究了温度对大白菜抽薹开花的影响。结果表明，随着2℃种子春化时间的延长，从播种到开花的时间缩短，叶片数减少。从春化开始到现蕾的总计天数来看，春化15 d的处理所需时间最短。而未经春化的对照处理则不能开花。在8℃和10℃条件下，03s205和03s206均能通过春化，但10℃条件下要求更长的持续时间。8℃处理15 d就可开花，而10℃处理要25 d才能通过春化。苗期35℃的持续高温可使春化15 d和24 d的材料发生春化逆转，但对苗龄大于12 d的植株无效。而18 h 23℃和6 h 35℃交替温度下，春化15 d的大白菜不发生春化逆转，仍能够开花。     

生物炭对大白菜幼苗生长的影响

以2个大白菜品种为试材,在常规育苗基质中添加不同比例的花生壳生物炭或玉米秸秆生物炭,研究生物炭对大白菜幼苗生长的影响。试验结果表明,生物炭添加有助于提升基质的通气性,与常规育苗基质相比增幅为 2.1%~42.1%,显着提升了C/N和速效钾含量,增幅分别为23.9%~131.2%和48.8%~297.2%,同时,生物炭添加降低了基质碱解氮与有效磷含量,降幅分别为10.4%~44.8%和7.1%~20.8%,基质毛管孔隙度降幅为14.0%~19.6%.在花生壳生物炭与常规育苗基质等体积比混合处理中,大白菜幼苗株高、茎粗、叶绿素含量、植株鲜干重及壮苗指数等最高,长势最佳,但出苗率最低。     

大白菜-结球甘蓝双单体异附加系的SSR鉴定及其特性

 【目的】筛选大白菜-结球甘蓝异附加系,利用SSR标记鉴定附加的外源染色体,并对异附加系特性进行研究。【方法】以大白菜-结球甘蓝异源三倍体（AAC）与二倍体大白菜（AA）回交一代的自交后代为试材,利用根尖染色体计数、甘蓝连锁群特异SSR标记等方法,筛选、鉴定大白菜-结球甘蓝异附加系。【结果】在BC1F2中筛选到2n=22的植株;该植株对位于甘蓝01连锁群的3对SSR引物和08连锁群的2对SSR引物的扩增结果与异源三倍体杂交种是一致的,而对位于其它7个连锁群的20对特异引物的扩增结果与大白菜一致,表明该植株附加的外源染色体与甘蓝的01、08连锁群相对应,为双单体异附加系;该双单体异附加系绝大多数花粉母细胞减数分裂终变期染色体构型为10Ⅱ+2Ⅰ,后期Ⅰ以11-11、10-12分离方式为主,后期Ⅱ产生了n=11配子。【结论】利用甘蓝连锁群相对于大白菜特异的SSR标记可以准确鉴定大白菜-结球甘蓝异附加系;获得了附加甘蓝01、08连锁群的大白菜双单体异附加系,为进一步合成附加甘蓝01或08连锁群大白菜-结球甘蓝单体和双体异附加系奠定基础。     

脱落酸和烯效唑对菜心品质特性的影响

[目的]以菜心品种油青四九(Brassica campestris L.ssp.chinensis var.utilis Tsen et Lee cv.Youqing 49)为材料,研究不同浓度脱落酸和烯效唑,分别在2～3、4～5、6～8叶期3个时期,单一和混合施用对菜心菜薹品质特性的影响。[方法]对菜薹VC、可溶性蛋白、硝酸盐、可溶性糖、还原糖及游离氨基酸总量进行定量分析。[结果]所有处理中,以6～8叶期脱落酸15 mg/L+烯效唑300 mg/L处理菜薹VC含量最高,以4～5叶期烯效唑400 mg/L处理菜薹可溶性蛋白含量最高。除3个时期的脱落酸20 mg/L处理、6～8叶期烯效唑400mg/L以及脱落酸20 mg/L+烯效唑400 mg/L外,其余处理均不同程度地降低了菜薹的硝酸盐含量。脱落酸和烯效唑处理对菜薹游离氨基酸含量的增加作用在2～3叶期效果较好。菜薹可溶性糖和还原性糖含量以2～3叶期的脱落酸20 mg/L+烯效唑300 mg/L处理和4～5叶期脱落酸15 mg/L+烯效唑300 mg/L处理较高。[结论]综合而言,以2～3叶期脱落酸20 mg/L+烯效唑300 mg/L处理菜薹品质较好。     

外源细胞分裂素BA对小白菜硫代葡萄糖苷含量的影响

研究外源细胞分裂素BA对小白菜硫代葡萄糖苷（硫苷）含量的影响,为提高小白菜硫苷含量提供参考。以不同浓度（0,0.2,5和20 mg·L^-1） BA进行处理,分析其对小白菜生长和硫苷含量的影响。随BA浓度的增加,小白菜鲜重有增加的趋势,其中5～20 mg·L^-1 BA处理显著增加了小白菜地上部鲜重。与对照相比,较高BA处理浓度（20 mg·L^-1）显著诱导了5-甲基亚磺酰戊基硫苷、3-丁烯基硫苷、4-戊烯基硫苷和总硫苷的含量,但在0.2 mg·L^-1 BA处理显著增加了4-戊烯基硫苷和2-苯乙基硫苷含量。5～20 mg·L^-1 BA处理显著抑制了1-甲氧基吲哚-3-甲基硫苷的含量,但对其他吲哚族硫苷含量并没有引起显著的变化。不同种类硫苷对不同浓度的BA处理有不同的响应,其中20 mg·L^-1 BA处理显著提高了小白菜总硫苷含量。