以野生型K326土培烟草为试验材料,对NtCCX2基因进行克隆与表达模式分析,明确其在烟草响应镉等胁迫应答中的作用.结果表明,NtCCX2基因全长2 464 bp,CDS区1 926 bp,编码641个氨基酸,具有CCX家族显著的特征,在跨膜区有2个α-重复区域:α1模式基序GNGAPD和α2模式基序G(N/D)SxGD.NtCCX2基因具有明显的时空表达特性,在幼苗期和旺长期叶中的相对表达量最高,在成熟期根和花中的相对表达量较高.NtCCX2基因启动子含有脱落酸(ABA)等激素信号以及抗逆相关的响应元件,在根和叶中的表达除了受干旱、盐和镉胁迫诱导外,还对ABA、茉莉酸甲酯(MeJA)和乙烯利产生不同的响应.其中,ABA处理2 h后,NtCCX2基因在根中相对表达量是Oh的3.7倍;MeJA处理8 h后,叶中NtCCX2基因相对表达量是Oh的2.1倍;乙烯利处理2h后,NtCCX2基因在根和叶中相对表达量均增加.降镉灵等降镉药剂能够下调该基因的表达.

为改善和提升自育品种秦烟96的外观质量和感官品质,以MS云烟97为母本、秦烟96为父本组配选育成雄性不育杂交种秦烟201,于2019年3月通过全国烟草品种审定委员会审定.该品种田间长势强,整齐一致,叶片易落黄、易烘烤;综合抗病性和经济性状均好于对照NC89;烤后烟叶外观质量、化学成分协调性、感官质量均优于NC89,物理特性与NC89相当.综合评价,秦烟201在品质、抗性、产量、适应性等方面能够较好兼顾,综合性状优良,适宜在北方烟区种植.

A field experiment using Qinyan 96 cultivar was conducted to investigatetheeffects of transplanting dates on yield and quality of flue-cured tobacco.The results showed that with postponement of transplanting dates, yield, average price, output value and percentage of medium and superior tobacco increased firstly,then declined. In addition, there was a significant impact of transplanting dates on chemical components of flue-cured tobacco, effect andchange trend in chemical components varied with differences in leaf site. Compared with the reference of the high quality flue-cured tobacco leaves, suitable degree of chemical components existed difference in various leaf positions. With postponement oftransplanting dates of flue-cured tobacco, chemical quality of flue-cured tobacco from four leaf positions increased firstly and then decreased. And chemical quality of flue-cured tobacco from cutters and lugs was better than that from tips and leaf. All resultssuggestedthat optimal transplanting datefor Qinyan96 was 10th-May in Luonan, and appropriate transplanting datecanimprove growth and development of flue-cured tobacco, andincrease yield and quality of tobacco leaf.

A field experiment was conducted to study the effect of different kinds of potassium (K) fertilizers on agronomic attributes, chemical components and economic values of flue-cured tobacco in two typical ecological zones in Shaanxi province. The results showed that K fertilizer had significant effect on leaf area. The effect of potassium nitrate was better than that of potassium humate in Longxian;the effect of potassium humate was the best, followed by mixed k fertilizer. K application increased contents of total sugar, reducing sugar, nitrogen, nicotine and potassium, and decreased the content of chlorine, and these effects varied with ecological zones. Leaf chemical composition was more harmonious with potassium humate or mixed K fertilizer treatment. In addition, main economic values increased significantly with K fertilizer treatment, and better effect was observed with treatment of mixed K fertilizer in Longxian, but potassium humate and mixed K fertilizer in Luonan. Overall, mixed K fertilizer was preferred in Longxian, and potassium humate or mixed K fertilizer in Luonan. K application was useful to optimize leaf chemical components, improved leaf quality and increase yield, but these effects varied with ecological zones.