可可种质资源多样性与创新利用研究进展

就可可种质资源在起源、分布、传播、分类、鉴定及种质创新与利用等方面取得的研究进展进行综述。可可属植物有22种,仅可可(Theobroma cacao)和大花可可(Theobroma grandiflorum)用于栽培。可可种质资源多样性丰富,其分类研究经历了传统形态学划分的Criollo、Forastero和Trinitario遗传类群到现代分子标记划分的Maran~on、Curaray、Criollo、Iquitos、Nanay、Contamana、Amelonado、Purús、Nacional和Guiana遗传类群。目前,可可的生产性品种选育仍以实生选种和芽变选种为主。分子标记的开发、遗传连锁图谱的构建和全基因组测序的完成,为实现可可分子标记辅助育种提供了技术保障。     

不同前茬作物对星油藤土壤肥力的影响

为探讨不同前茬作物对星油藤土壤肥力的影响,在云南省西双版纳普文镇开展了5种不同前茬作物(茶树-星油藤、水稻-星油藤、香蕉-星油藤、玉米-星油藤、空地-星油藤)对星油藤根际和非根际土壤pH值、土壤电导率、有机质、全氮、全磷、全钾及微量元素的影响研究(以空地-星油藤为对照)。结果表明:不同前茬作物对星油藤根际与非根际土壤pH、电导率与空地土壤pH、电导率均呈显著差异。微量元素全锰、全铁、全锌和全铜的含量低于世界和全国土壤平均水平,重金属元素全锌和全铜单项污染值小于1。以土壤中的有机质、全氮、全磷、全钾的含量综合评价不同前茬作物对星油藤的土壤肥力水平依次为:玉米-星油藤茶树-星油藤香蕉-星油藤水稻-星油藤空地-星油藤。综合考虑,以前茬作物为玉米和茶树的星油藤土壤肥力较好。     

割手密种质资源遗传多样性的ISSR分析

为探讨国内割手密种质资源的遗传多样性,本研究采用ISSR分子标记对采自8省的52份割手密种质资源进行了分析。结果表明,22条ISSR引物共扩增出127条条带,其中多态性条带121条,多态率达95.3%。材料间遗传相似系数GS在0.60~0.91之间。UPGMA聚类分析结果表明:在遗传相似系数0.72时52份材料可分为4大类;ISSR分析结果显示,割手密遗传多样性丰富,可以用ISSR对割手密进行分子水平的鉴定和遗传多样性研究。     

Estimating theoretical radiation‐use efficiency for kale crops

Establishing the radiation‐use efficiency (RUE) of forage brassica crops will aid our understanding of their photosynthetic performance. The concept of RUE has been developed for cereals and legumes, but there is limited information for forage brassica crops. Three experiments defining the influence of different sowing dates on ‘Gruner’ kale (Brassica oleracea acephala L.) dry matter production were conducted at Hastings (Hawkes Bay) and Lincoln (Canterbury) in New Zealand between 2002 and 2009. These trials were also evaluated for radiation interception and RUE. Delayed sowing increased RUE in two out of three experiments across sites: from 1·93 g MJ^?1 photosynthetically active radiation (PAR) for December‐sown crops to 2·72 g MJ^?1 PAR (P < 0·001) for January‐sown crops at Hastings and from 1·50 for September‐sown crops to 2·00 g MJ^?1 PAR (P < 0·001) for November‐sown crops at Lincoln. The different sowing dates and years of experimentation provided a range of mean temperatures (from 13 to 16°C) during the vegetative period. Across years and sowing dates, RUE was strongly correlated with mean temperature (R² = 0·81) and sowing date (R² = 0·64), but weakly correlated with season length (R² = 0·11) and dry matter (R² = 0·002). There was also a strong correlation (R² = 0·83) between sowing date and mean temperature. The increase in RUE with delayed sowing was therefore mainly attributed to increased mean temperatures. Radiation‐use efficiency increased at about 0·41 g MJ^?1 for each 1°C increase from 13 to 16°C.     

稻瘟病抗性基因的克隆及应用研究进展

稻瘟病是水稻三大病害之一,每年都给水稻生产造成巨大损失,挖掘并合理利用品种自身抗性是解决稻瘟病危害的最有效途径。本文综述了水稻稻瘟病抗性基因克隆、功能标记开发以及稻瘟病抗性分子标记辅助选择育种研究进展,为进一步克隆、研究、应用稻瘟病抗性基因提供理论指导。     

种植密度对小麦籽粒淀粉含量和晶体特性的影响

为探究种植密度对小麦籽粒淀粉品质的调控效应,以2个小麦品种(轮选987和济麦22)为材料,分析了3个不同种植密度(150、300、450万株·hm-2)下小麦籽粒淀粉含量和晶体特性。结果表明,种植密度影响小麦籽粒淀粉的积累和组成。随种植密度的增大,直链淀粉含量呈先降后升的趋势,而支链淀粉和总淀粉含量表现为先升后降。淀粉晶体呈典型的A型特征,且不受种植密度影响。种植密度明显影响淀粉颗粒内部的结晶程度,表现为随种植密度的增大,相对结晶度先升后降。同时,种植密度改变了淀粉X-衍射图谱中各峰的精细位置和相对强度,说明种植密度对淀粉颗粒内部结晶区的晶胞结构或微晶排列也存在一定影响。淀粉的相对结晶度与直链淀粉含量呈负相关,与支链淀粉含量呈正相关。     

小麦次生根数相关分子标记的挖掘

为了给小麦根系性状的遗传改良提供参考依据,以196份小麦自然群体为材料,于2013年拔节期和2014年越冬前、拔节期统计其次生根数,利用185对SSR标记对其进行基因型分析,采用TASSLE软件的GLM和MLM模型进行标记与性状的关联分析。结果表明,两种模型共同关联到32个显著标记位点,分布于14条染色体上。其中Barc81(1BL)、Wmc617(4DS)和Gwm190(5DS)在不同环境下表现稳定,且前人未曾报道。进一步对稳定位点进行有利等位变异分析,共挖掘出3个有利等位变异,其中Barc81-A180增效效应最大,同时鉴定出烟农24、烟农2415及冀麦34等20份材料携带有利等位变异。     

5种细胞质雄性不育小麦败育过程中活性氧代谢保护酶的响应

为了解异质雄性不育小麦败育过程中活性氧代谢中几种保护酶的变化特点,以5种小麦雄性不育系U116A、Ju116A、Va116A、C6116A、K116A及其相应保持系116B为材料,分析了小麦雄性不育系在花药不同发育时期的过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性与保持系的差异。结果表明,不育花药的POD活性自单核早期后均比同一发育时期的可育花药高;自单核晚期开始,不育系CAT活性总体上呈下降趋势,而可育系则呈升高趋势;受试材料花药中SOD活性总体呈上升趋势,且不育系高于保持系。经差异分析,不育系U116A、Ju116A、Va116A、C6116A的败育关键期是单核晚期,而K116A的败育关键期则是单核晚期至二核期。以上结果说明,5种异质小麦雄性败育时期有所不同,并且雄性育性与POD、CAT和SOD活性密切相关。     

假叶树组织培养植物激素应用筛选试验

采用假叶树的幼嫩茎段为外植体组织培养,对加入适合的植物激素作筛选试验,结果表明：MS＋ZT 2.0 mg·L^-1＋IBA 0.5 mg·L^-1培养基愈伤组织的诱导率最高;MS＋ZT 1.5 mg·L^-1＋IBA 0.2 mg·L^-1培养基分化不定芽效果最佳,并且在MS＋ZT 1.0 mg·L^-1-1.5 mg·L^-1＋IBA 0.2 mg·L^-1培养基上继代增殖培养增殖系数可达4-5倍;不定芽在1/2MS＋NAA 1.0＋1.5 g·L^-1活性炭的培养基上,生根率达100%;生根小苗移栽珍珠岩与泥炭土（1∶1）基质上,成活率达95%以上。     

Palmitic Acid and Ergosta-7,22-dien-3-ol Contribute to the Apoptotic Effect and Cell Cycle Arrest of an Extract from Marthasterias glacialis L. in Neuroblastoma Cells

We describe the effect of a chemically characterized lipophilic extract obtained from Marthasterias glacialis L. against human breast cancer (MCF-7) and human neuroblastoma (SH-SY5Y) cell lines. Evaluation of DNA synthesis revealed that both cell lines were markedly affected in a concentration-dependent way, the SH-SY5Y cell line being more susceptible. Cell cycle arrest was observed, an effect induced by the sterol, ergosta-7,22-dien-3-ol, present in the extract. Morphological evaluation of treated cells showed the advent of lipid droplets and chromatin condensation compatible with apoptosis, which was confirmed by the evaluation of caspase-3 and -9 activities. Palmitic acid was the main compound responsible for this apoptotic effect by a ceramide-independent mechanism that involved endoplasmic reticulum (ER)-stress with upregulation of CCAAT/-enhancer-binding protein homologous protein (CHOP).