一个新的水稻花器官突变体的鉴定和基因定位

在水稻（Oryza sativa）品种台中65的组培后代中发现一个花器官发育异常突变体flower organ number6（fon6）,其主要表型为：双子房,多柱头,7-8枚雄蕊。遗传分析表明,该突变表型由一对隐性基因控制。以该突变体与籼稻3037杂交的F2代分离群体作为定位群体,利用STS标记将与突变性状相关的基因定位于第6染色体短臂上STS标记PL4和PL5之间约480kb的范围内。该研究结果为进一步的基因克隆及功能研究奠定了基础。     

巴郎山高山及亚高山草甸花卉植物生物量海拔梯度格局

采用野外调查方法,研究卧龙巴郎山高山及亚高山草甸不同海拔梯度下花卉植物生物量的变化格局,并进行土壤因子分析,结果表明:花卉植物地上生物量随海拔的升高呈单峰曲线变化,在3500 m处达到峰值,花-果、茎、叶生物量的变化趋势与地上生物量一致;地下生物量随海拔的升高呈U型曲线变化.随海拔的升高,土壤酸性增强,水解氮和全钾含量显著升高,土壤有机质、全氮和有效磷的含量显著降低,花卉植物地上生物量随土壤pH值及全氮、速效钾含量的升高显著增大;地下生物量随土壤有机质、有效磷含量的升高显著增大,随全钾、水解氮含量的升高显著减小.     

无花瓣油菜雄蕊心皮化突变体细胞学观察及基因表达分析

油菜是我国重要的油料作物,油菜花器官具有典型的十字花科特点,无花瓣油菜在花期不存在花冠层,这种特点有助于提高油菜产量,预防茵核病的传播。雄蕊心皮化是指花器官的雄蕊结构被具有类似于雌蕊结构的器官代替,这不仅造成了花器官结构的变化也导致了雄性不育。本文通过对无花瓣油菜雄蕊心皮化突变不育分离群体中的雄性可育株和不育株的比较研究,发现心皮化现象是由遗传因素引起的。细胞学观察发现,雄蕊心皮化在花器官发育的早期就已经产生,心皮化的雄蕊中着生类似于胚珠的结构,其顶端细胞的形态和排列方式也与雌蕊柱头相似。花发育相关基因的表达分析表明,B组基因彳丹在不育株3轮花器中的表达都比可育株低,特别是在第二轮花器官中这种差异最为突出。而A组基因AP1在不育株第二轮花器官中的表达量较可育株高。c组基因AGL8、SHPI、SHP2、NAP在不育株心皮化的第二轮花器官中表达都较可育株中高。     

Reproductive biology and success of invasive Australian acacias in Portugal

Reproductive traits are crucial for the establishment and maintenance of populations in new areas, and therefore for the invasion process. This work aimed to study the reproductive biology of four aggressive invasive Australian Acacia spp. in Portugal. Fruit and seed set, seed weight and germinability, and seedling growth were assessed for self‐ and outcross treatments in invasive populations of A. dealbata, A. longifolia, A. melanoxylon and A. saligna. Acacia spp. showed different investments in the production of reproductive units and in natural reproductive success, with A. dealbata, the most aggressive species, having the highest investment and reproductive success. Acacia melanoxylon showed a different reproductive strategy, andromonoecy, contrasting with the other hermaphroditic species. Acacia spp. were shown to be predominantly self‐incompatible, but a low level of spontaneous selfing enabled the production of viable offspring. Acacia dealbata and A. longifolia suffered pollen limitation. Self‐progeny had lower viability than progeny from outcrossing for A. dealbata and A. melanoxylon. Acacia spp. did not show higher compatibility rates in comparison with the native area. They had low fruit set but, as a result of their massive flower production, their realized reproductive success was high and could have contributed to the invasion. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174 , 574–588.     

多效唑和缩节胺对现蕾前忍冬枝叶生长及花蕾性状和有效成分含量的影响

以忍冬品种‘九丰一号’(Lonicera japonica‘Jiufeng 1’)为实验材料,采用叶面喷施方法研究了不同质量浓度多效唑和缩节胺对现蕾前(抽枝生长初期)枝叶生长和叶片叶绿素含量以及花蕾性状和花蕾中绿原酸和总黄酮含量的影响。结果显示:分别喷施100、400、700和1 000 mg·L-1多效唑和50、100、150和200 mg·L-1缩节胺后,多数处理组的开花枝条数、着花节数和叶绿素含量较对照CK1(水)有不同程度提高,但叶面积差异不明显。随处理时间延长,各处理组枝条节间长度总体上呈逐渐增加的趋势,其中多数处理组枝条节间长度增长缓慢。各处理的花蕾长度、百蕾鲜质量和干质量总体上小于CK1,而花蕾折干率、总黄酮含量和绿原酸含量显著或不显著高于CK1。此外,在喷施多效唑和缩节胺的同时喷施质量体积分数1.0%尿素和质量体积分数0.1%硼砂,忍冬的叶面积、着花节数、花蕾长度、折干率、百蕾鲜质量和干质量总体上有所提高,而绿原酸含量降低,但各指标的差异总体较小。研究结果表明:喷施适量多效唑和缩节胺可调控忍冬枝条生长,并能提高花蕾中总黄酮和绿原酸含量。     

Acceptance and suitability of four plant substrates for rearing Orius sauteri (Hemiptera: Anthocoridae)

Orius sauteri (Poppius) is an important hemipterous predator that has been mass-reared for biological control of numerous pests in protected crop-production systems. To find a good oviposition substrate for mass-rearing this predator under insectary conditions [25°C, 65 ± 5% relative humidity, and a photoperiod of 16:8 (L:D) h], we compared kidney bean, soybean, broad bean sprouts and fresh leaves of kidney bean. We found that O. sauteri made more punctures and laid more eggs in kidney bean sprouts than in the other substrates examined. However, there were no significant differences among substrates in the proportion of punctures receiving eggs. Female O. sauteri laid the most eggs (as many as 68 eggs) in kidney bean sprouts and also had the shortest pre-oviposition period on this plant material. In addition, there were no significant differences in total oviposition durations or female longevity among the four plant substrates. The hatch rates of nymphs in the sprouts and leaves of kidney bean (>90%) were higher than those in soybean and broad bean sprouts. Thus, we found that the kidney bean sprout was the most suitable substrate for mass-rearing of O. sauteri.     

A chalcone isomerase‐like protein enhances flavonoid production and flower pigmentation

Flavonoids are major pigments in plants, and their biosynthetic pathway is one of the best‐studied metabolic pathways. Here we have identified three mutations within a gene that result in pale‐colored flowers in the Japanese morning glory (Ipomoea nil). As the mutations lead to a reduction of the colorless flavonoid compound flavonol as well as of anthocyanins in the flower petal, the identified gene was designated enhancer of flavonoid production (EFP). EFP encodes a chalcone isomerase (CHI)‐related protein classified as a type IV CHI protein. CHI is the second committed enzyme of the flavonoid biosynthetic pathway, but type IV CHI proteins are thought to lack CHI enzymatic activity, and their functions remain unknown. The spatio‐temporal expression of EFP and structural genes encoding enzymes that produce flavonoids is very similar. Expression of both EFP and the structural genes is coordinately promoted by genes encoding R2R3‐MYB and WD40 family proteins. The EFP gene is widely distributed in land plants, and RNAi knockdown mutants of the EFP homologs in petunia (Petunia hybrida) and torenia (Torenia hybrida) had pale‐colored flowers and low amounts of anthocyanins. The flavonol and flavone contents in the knockdown petunia and torenia flowers, respectively, were also significantly decreased, suggesting that the EFP protein contributes in early step(s) of the flavonoid biosynthetic pathway to ensure production of flavonoid compounds. From these results, we conclude that EFP is an enhancer of flavonoid production and flower pigmentation, and its function is conserved among diverse land plant species.     

Precise spatio‐temporal modulation of ACC synthase by MPK6 cascade mediates the response of rose flowers to rehydration

Drought is a major abiotic stress that affects the development and growth of most plants, and limits crop yield worldwide. Although the response of plants to drought has been well documented, much less is known about how plants respond to the water recovery process, namely rehydration. Here, we describe the spatio‐temporal response of plant reproductive organs to rehydration using rose flowers as an experimental system. We found that rehydration triggered rapid and transient ethylene production in the gynoecia. This ethylene burst serves as a signal to ensure water recovery in flowers, and promotes flower opening by influencing the expression of a set of rehydration‐responsive genes. An in‐gel kinase assay suggested that the rehydration‐induced ethylene burst resulted from transient accumulation of RhACS1/2 proteins in gynoecia. Meanwhile, RhMPK6, a rose homolog of Arabidopsis thaliana MPK6, is rapidly activated by rehydration within 0.5 h. Furthermore, RhMPK6 was able to phosphorylate RhACS1 but not RhACS2 in vitro. Application of the kinase inhibitor K252a suppressed RhACS1 accumulation and rehydration‐induced ethylene production in gynoecia, and the protein phosphatase inhibitor okadaic acid had the opposite effect, confirming that accumulation of RhACS1 was phosphorylation‐dependent. Finally, silencing of RhMPK6 significantly reduced ethylene production in gynoecia when flowers were subjected to rehydration. Taken together, our results suggest that temporal‐ and spatial‐specific activation of an RhMPK6‐RhACS1 cascade is responsible for rehydration‐induced ethylene production in gynoecia, and that the resulting ethylene‐mediated signaling pathway is a key factor in flower rehydration.