晚抽薹大白菜系列品种的选育

对大白菜用筛选出的冬性特强、抽薹特晚株纱和不同生态型品种进行了多亲复合杂交,其后代又利用设计出现的雄性不育株,隔代在大群体中使之充分异交,经多代集团性轮回选择,育出５个具有不同生态特点的基础群体,而后再用不同的选育途径和方法育成常规品种、质核杂种和一代杂种等。选育出的两个系统已通过省级审定,示范推广面积近１０万ｈｍ＾２。     

菜薹抽薹相关基因BrcuDFR-like/BrcuAXS 的克隆与表达特性分析

 为了预测抽薹相关基因BrcuDFR-like/BrcuAXS 的功能,通过PCR 和RACE 的方法克隆了菜薹BrcuDFR-like/BrcuAXS 基因的cDNA 和gDNA 全长序列。结果表明：该基因编码区全长1 332 bp,编码312 个氨基酸残基。对应的gDNA 全长为2 460 bp,含有8 个外显子和7 个内含子,内含子总长为1 042bp,其中第3 个内含子最长,为401 bp。内含子中含有多个基本转录元件和顺式作用元件,如光应答元件、赤霉素响应元件、参与抗性和胁迫应答元件、热响应元件、WRKY 转录因子的结合位点及干旱胁迫元件MYB 转录因子结合位点等。利用半定量RT-PCR 分析表达模式,发现BrcuDFR-like/BrcuAXS 随菜薹花芽形态逐步建成直至抽薹开花,其表达量逐渐增强,与其它物种DFR-like 基因的表达模式更吻合,由此预测该基因在菜薹生长发育阶段编码DFR-like 酶的可能性大于编码AXS 的可能性,其功能可能与菜薹营养分生组织向花分生组织转变有关。     

小株型大白菜新品种京春娃4号的选育

京春娃4号是由两个自交不亲和系07QX4B和0841杂交配制而成的小株型大白菜一代杂种。早熟,生长期55～60 d(天),株型较矮,外叶深绿色,中肋浅绿色,叶球筒形、叠抱,叶球高22～23 cm、直径13～14 cm,球内叶切面为均匀深黄色,单球质量约1.4 kg,每667 m~2净菜产量5 000 kg左右。耐抽薹性强,对黄萎病的田间抗性强于对照春月黄、玲珑黄012和耐寒金皇后,品质脆甜。适宜作大娃娃菜种植,每667 m~2可定植6 000株,适合北京、云南地区春、秋季露地种植,张家口坝上、甘肃、云南等高冷地区(海拔800～1 800 m)夏季露地种植。     

A genetic analysis of the number of cells,length of cell,and gibberellic acid sensitivity in sugar beet and their relation to bolting mechanism

Summary Three series of full-sib progenies and parental inbred lines or populations were used to study the inheritance of the number of cells and length of cell along the hypocotyl length, and the response to gibberellic acid in young plants of sugar beet. Variance components were determined by using a factorial cross design. There were no significant estimates of non-additive genetic variation for either cellular characters. Both additive and non-additive genetic variance were responsible for the variability of stem length after GA3 treatment. It is concluded that additive type genes predominantly control the number of cells in all series. The length of cell had significant additive variances in most cases, but it was indeed markedly influenced by environmental factors. Number of cells (cell division rate) and GA3 sensitivity in young plants even before vernalization were related to bolting tendency. Bolting-susceptible genotypes generally expressed higher stem length in the response to added GA3 as compared to the bolting-resistant genotypes. However, some genotypes bolted easily in the field but reacted weakly to the GA3 treatment and vise versa. Genotypes that were susceptible to bolting and/or sensitive to GA3 had a specific range (intermediate) of cell number. There were, however, some genotypes containing an intermediate number of cells which demonstrated low bolting. These responded faintly to gibberellin treatment. The results suggest that several physiological requirements have to be fulfilled before bolting can occur, and that other plant characters interfere with the bolting phenomenon.     

A marker-assisted analysis of bolting tendency in sugar beet (Beta vulgaris L.)

Bolting tendency in sugar beet varies among breeding lines and cultivars. Four crosses were made between breeding lines susceptible and resistant to bolting in order to study the genetic basis of bolting tendency. Bolting percentage in F₂, after 8 weeks of low temperature treatment, varied among the crosses, suggesting a complicated genetic control of bolting tendency. Different segregation ratios were observed, in particular, between families derived from the bolting F₁ plants and those from their non-bolting siblings, the former families showing a significantly higher bolting percentage than the latter. A marker-assisted analysis with seven isozyme loci, Ak1, Gdh2, Idh1, Lap, Mdh1, Pgi2 and Pgm1, revealed that a locus with marked effect on bolting tendency was located near Idh1. Because of a close linkage of Idh1 with B for annuality, the gene tagged by Idh1 appeared to be equivalent or similar to B′ for easy bolting allelic to B as reported by Owen et al. (1940). The results obtained suggest that the B locus may not only have an important role in determining growth habits but also control various degrees of bolting tendency in individual sugar beet plants. A linked pair, Ak1-Lap, and Pgi2 also were found to affect bolting tendency, although their effects varied depending on the crosses and families tested. This revised version was published online in July 2006 with corrections to the Cover Date.     

晚抽薹大白菜新品种比较试验

将新选育的 4个晚抽薹大白菜品系及 3个对照品种露地春播 ,结果比较表明 :4个新品系在经济性状、产量、耐抽薹性等方面均优于对照 ,并各具优点。 3号品系产量高 ,包心早 ;2号品系净菜率高 ,耐抽薹性强 ,商品性好 ;4号品系抗病性强 ,经济性状良好 ,耐抽薹性强 ;1号品系在比较的几个方面相对于2、3、4号品系虽不突出 ,但明显优于对照品种。     

收获期对胡萝卜产量和抽薹及发病的影响

通过春种胡萝卜的３ 个不同收获期对其植物学性状、产量、抽薹率及软腐病发病率影响的调查分析，摸索出其较适宜的收获期。     

保护地甘蓝——冬甘二号的选育

冬甘二号是适合保护地栽培的春甘蓝品种 ,具有早熟、高产、优质、耐裂性强、整齐度好、冬性强等特性。植株开展度为 47.2 cm× 46 .6 cm,外叶 1 1～ 1 4片 ,叶绿色 ,叶球近圆形 ,单球重 0 .85～ 1 kg,紧实度 0 .8,定植后 45～ 5 0天可以收获。适合北方地区栽培     

萝卜抽薹开花相关基因的研究进展

通过构建萝卜抽薹开花相关基因的cDNA文库,获取大量的EST序列,并与十字花科模式植物拟南芥、白菜等进行比较基因组学研究,研究结果显示:萝卜与拟南芥、白菜等植物基因组具有很高的同源性,控制抽薹开花的相关基因在不同物种中具有保守性。拟南芥抽薹研究表明,抽薹开花过程受多基因控制,具有多种调控途径。抽薹开花是一个复杂的过程,其中FLC、FT、LFY等基因处于关键位置。目前这些关键基因在萝卜EST序列中已经发现了同源片段,并进行了一些基因克隆,结合萝卜基因组测序的完成,未来萝卜抽薹研究将进入基因功能验证和全基因组调控模式研究之中。