芥蓝—菜薹种间三倍体回交子代染色体数鉴定及单体异附加系的选育

为创造CC染色体组附加A染色体组的单体异附加系,以芥蓝—菜薹种间三倍体(CCA)为材料,采用人工杂交、形态和细胞学鉴定及核型分析等方法,比较了芥蓝—菜薹种间三倍体与其亲本芥蓝(CC)正、反交的结实性,分析了杂交子代的染色体数及频率分布,并对筛选出的单体异附加系进行了系统研究。结果表明:CCA×CC和CC×CCA的结籽率分别为0.28%和0.63%;在鉴定的88个CC×CCA的子代中,全部为2n=18的整倍体植株;在鉴定的156个CCA×CC的子代中,(2n+1)～(2n+9)等各类非整倍体均有存在,其中附加1条染色体的1个、附加2条染色体的16个;形态学标记鉴定和核型分析显示附加1条染色体的那个子代植株为单体异附加系CC+A9;在减数分裂终变期,单体异附加系CC+A9的A9染色体常与一对C组的染色体发生局部联会,两者间存在着部分同源关系;单体异附加系CC+A9的n+1雌、雄配子均有一定传递率,分别为18.75%和9.82%;单体异附加系CC+A9自交获得了1株双体异附加系。     

食用羽衣甘蓝绿雁贮藏保鲜期研究

为了大量推广应用新育成高档珍稀叶菜食用羽衣甘蓝新品种绿雁,分设6个不同处理研究贮藏保鲜期。试验结果表明,绿雁的商品叶片室温16～21℃3个处理,以保鲜膜包装留孔保鲜方法最适,可达4～6d,鲜质量损失12．36％;冰箱O～4℃3个处理,保鲜盒内净存放,每天打开交换空气1—2min保鲜方法最适,可达36d,鲜质量损失17．97％。绿雁的保鲜期较常温延长了30d左右,受低温和环境空气影响各15d。说明食用羽衣甘蓝等绿色蔬（叶）菜高效低廉的贮藏保鲜方法是尽力保持较低的温度（一般在0—10℃）和处理好贮藏空间空气的流通情况。     

观赏羽衣甘蓝新品种‘粉玉’

观赏羽衣甘蓝新品种‘粉玉’是以胞质雄性不育系‘CMS2002-18’为母本,自交不亲和系‘2000-13’为父本杂交育成。为矮生皱叶类型,株高30 ~ 35 cm;心叶紫红色,外叶叶基红色,边缘绿色;叶紧凑,开展度35 ~ 40 cm;色泽艳丽,群体整齐美观,观赏价值高,耐寒,生长势强。     

观赏羽衣甘蓝新品种‘红青花’与‘红海星’

‘红青花’与‘红海星’均为地被类型观赏羽衣甘蓝杂交种。‘红青花’植株低矮紧凑,内叶粉红色,波浪形。‘红海星’叶深红色,叶缘深裂且多褶皱。二者叶色鲜艳,叶形典雅,观赏价值高,变色早,耐寒,耐抽薹,观赏期长。     

铁浓度对水培芥蓝生长、品质及生理特性的影响

水培芥蓝时常遇到缺铁造成植株矮小、品质降低的现象,但高铁浓度培养易引起铁中毒产生生理障碍而抑制芥蓝生长。以EDTA-Fe为铁源,研究了不同铁浓度水平(2.8 mg/L、5.6 mg/L、8.4 mg/L、11.2 mg/L和14.0 mg/L)对水培芥蓝生长、品质及生理特性的影响。结果表明:芥蓝植株鲜重和株高随营养液供铁浓度的增加而增加,但铁浓度超过8.4 mg/L后植株鲜重无显著增加,株高则下降。芥蓝薹叶与薹茎的可溶性蛋白、可溶性糖和维生素C含量都随铁浓度的增加而显著增加,超过8.4 mg/L后薹叶的可溶性蛋白含量不再显著增加,超过11.2 mg/L时薹茎的可溶性蛋白、薹叶与薹茎的可溶性糖含量都不再显著增加。叶片叶绿素含量、薹叶CAT和POD活性均随铁浓度增加呈先增加后下降的趋势,至8.4 mg/L时达到最高。根系活力随着铁浓度的增加呈先增加后下降的趋势,至8.4 mg/L时达到最高。植株全铁含量也随着铁浓度增加而先升高后下降,薹叶全铁含量至8.4 mg/L处理达到最高,薹茎与根全铁含量11.2 mg/L时最高。本试验条件下水培芥蓝最适合的铁浓度是8.4 mg/L,可获得最佳的生物量和经济性状。     

芥蓝感染核盘菌过程中活性氧和芥子油苷的变化

 分析了核盘菌侵染芥蓝过程中,芥蓝的发病症状、含水量、电导率、活性氧和芥子油苷的变化。结果表明,在侵染过程中,侵染部位产生褐色病斑,并逐渐扩大到全叶。叶片含水量逐渐下降,电导率不断上升,活性氧（过氧化氢和超氧阴离子）大量累积,吲哚–3–甲基芥子油苷、4–甲氧基–吲哚–3–甲基芥子油苷、1–甲氧基–吲哚–3–甲基芥子油苷和烯丙基芥子油苷含量先上升后下降,3–丁烯基芥子油苷和2–羟基–3–丁烯基芥子油苷含量逐渐下降。研究表明芥子油苷,特别是吲哚类芥子油苷可能参与芥蓝对核盘菌侵染的防卫反应。     

芥蓝BC_3代Ogura CMS育性恢复材料的创制及Rfo基因传递和背景分析

【目的】创制Ogura细胞质不育(Ogura CMS)的恢复系是利用Ogura CMS种质资源的有效途径。本研究基于已获得的BC2代育性恢复单株15Q23,继续用芥蓝进行回交,通过分析育性恢复基因Rfo的传递效率,及BC3代Rfo阳性株的遗传背景、育性表现、结实性和倍性,从而加速甘蓝类蔬菜Ogura CMS恢复材料的创制,获得甘蓝类蔬菜Ogura CMS恢复系。【方法】以BC2代育性较好的单株15Q23为父本,Ogura CMS芥蓝15Y102为母本进一步回交,利用Rfo特异分子标记对所有回交后代进行筛选,计算BC3代Rfo传递效率,并调查BC3代Rfo阳性单株的形态特征、育性恢复情况、结实性、倍性;选取遗传背景近于芥蓝、结实较好的重点单株继续回交获得BC4代,分析BC4代Rfo传递效率和阳性单株倍性。【结果】在开花的不同时期,单株15Q23花粉活力差异明显,以不同时期的花粉进行回交的结实性也存在极显著差异(P0.01),平均结实率为0.07粒/授粉花蕾(7%)。利用Rfo特异标记对获得的BC3代单株进行苗期筛选,结果表明,Rfo可稳定传递,遗传背景分析结果表明,BC3代单株与芥蓝15Y102遗传相似系数在0.81—0.92,遗传背景比BC2代单株15Q23(0.73)更近于芥蓝,形态标记聚类结果与遗传背景标记聚类结果一致。形态观察发现,BC3单株形态特征都近于芥蓝,但生长势较亲本芥蓝更强;倍性鉴定结果表明,多数BC3后代接近于四倍体。开花后观察34个BC3后代单株的育性,有Rfo标记的单株育性均得到恢复。但不同单株间花粉活力存在差异,单株16Q1-4、16Q1-7、16Q1-10在整个花期花粉活力一直在75%以上。利用亲本芥蓝对花粉活力较好的Rfo阳性单株(花粉活力50%)进行回交,以单株16Q1-4和单株16Q1-10当父本时结实性最好,结实率分别为15%和9%,显著高于BC2代阳性单株15Q23(7%,P0.05)。BC4代单株中Rfo可以稳定传递,Rfo传递效率接近33%;对以16Q1-4为父本回交获得的24株阳性株进行倍性检测,不同单株间倍性差异较大,其中3株的荧光峰值和亲本芥蓝相近,倍性近于芥蓝。【结论】利用芥蓝对种间杂交六倍体Rfo阳性株进行第3、第4代回交,Rfo可稳定传递,成功获得了遗传背景、形态特征近于亲本芥蓝,结实性较BC2代单株15Q23显著提升的BC3代Ogura CMS育性恢复材料16Q1-4和16Q1-10。     

A method for evaluating bolting-resistance in Brassica species

Kale (Brassica oleracea var. acephala), Chinese cabbage (B. campestris ssp. pekinensis), chikale (B. campestris ssp. pekinensis × B. oleracea var. acephala hybrid) and turnip (B. campestris spp. rapifera) were studied. The proper plant size (number of true leaves) for the beginning of vernalization treatment was determined. All vernalization experiments commenced when the plants were 4 weeks old, with 5–7 true leaves. Plants were classified as bolters either through the visible appearance of flower buds at the apex, or by making longitudinal cuts through the apex if the flower buds were not visible. Cut plants with a pointed apex were classified as bolters. A definite relationship between the number of true leaves and bolting was observed for kale, the more difficult biennial species.     

羽衣甘蓝种质创新与新品种选育Ⅱ.生育期及在杂种一代中的遗传表现

作者利用引进的国外羽衣甘蓝杂种一代品种创造了40余份新种质,选育出耐冻性增强3～7℃、晚抽薹15～45 d、观赏性优的“冬春1-19号”系列羽衣甘蓝杂种一代新品种.本文报道羽衣甘蓝创新种质生育期及在杂种一代中的遗传表现研究结果.     

Economic impact of Turnip mosaic virus, Cauliflower mosaic virus and Beet mosaic virus in three Kenyan vegetables

Screenhouse experiments conducted in Kenya showed that inoculation of cabbage seedlings with Turnip mosaic virus (TuMV), either alone, or in combination with Cauliflower mosaic virus (CaMV), reduced the number and weight of marketable harvested heads. When viruses were inoculated simultaneously, 25% of cabbage heads were non-marketable, representing 20-fold loss compared with control. By contrast, inoculation with CaMV alone had insignificant effects on cabbage yield. This suggests that TuMV is the more detrimental of these pathogens, and its management should be a priority. Early exposure to TuMV produced cabbages that were 50% lighter than non-infected plants, but later infection was less damaging suggesting that controlling virus infection at the seedling stage is more important. TuMV was far less damaging to kale than it was to cabbage; although high proportions of TuMV-inoculated kale plants showed symptoms (>90%), the marketability and quality of leaves were not significantly reduced, and no clear relationship existed between timing of infection and subsequent crop losses. Early inoculation of Swiss chard with Beet mosaic virus (BtMV) significantly impaired leaf quality (∼50% reduction in marketable leaf production), but the impact of disease was greatest in plants that had been inoculated at maturity, where average leaf losses were two and a half times those recorded in virus-free plants. Disease-management of BtMV in Swiss chard is important, therefore, not only at the seedling stage, but particularly when plants are transplanted from nursery to field.