广东景天科植物新记录属——石莲属

报道发现于阳山县的广东省植物新记录属,即景天科石莲属(Sinocrassula Berger),描述新记录种石莲[S. indica(Decne.) Berger]的主要形态特征。凭证标本存放于南方医科大学植物标本馆。     

Isolation and characterization of microsatellite loci from Acacia nilotica ssp. indica (Mimosaceae)

Five microsatellite loci are presented for prickly acacia, Acacia nilotica ssp. indica (Benth.) Brenan, an introduced weed of national significance in Australia. These microsatellite loci were obtained through the construction of an enriched library and their use will enable us to determine the genetic origin and extent of genetic diversity of this weed in Australia.     

Mechanisms contributing to the competitive success of the invasive fruit fly Bactrocera invadens over the indigenous mango fruit fly, Ceratitis cosyra: the role of temperature and resource pre-emption

We investigated the influence of temperature and infestation sequence on interspecific competition between two fruit flies: an invasive ( Bactrocera invadens Drew, Tsuruta & White, ( B ) and a native ( Ceratitis cosyra Walker , C ) (both Diptera: Tephritidae) species. Mango fruits [ Mangifera indica L. (Anacardiaceae)] were co-infested with larvae at different constant temperatures (15, 20, 25, and 30 °C) and relative humidity of 50 ± 8%, using different infestation sequences at each temperature ( BC together; BC/CB 1, 2, and 3 days apart). There were significant effects of competition in most experimental treatments, resulting in reduced larval survival, pupal mass, and adult emergence for both species. At most of the infestation/temperature combinations, C. cosyra was clearly the inferior competitor. The only exception was at 20 °C when the outcome depended on the sequence of infestation: no C . cosyra survived when the sequence was BC , but more C . cosyra than B . invadens survived when it was CB . At 15 °C, all C. cosyra larvae died, while the development of B. invadens was prolonged and adult emergence reduced. We conclude that resource pre-emption and fluctuations in temperature in mango agroecosystems help to explain observed shifts in dominance between B. invadens and C. cosyra on mango in many parts of Africa. The small window of competitive superiority for C. cosyra at 20 °C and CB infestation sequence, together with other factors such as fecundity and alternative hosts, may allow for co-existence in some environments.     

Reproductive biology of the greater bandicoot rat Bandicota indica （Rodentia： Muridae） in the rice fields of southern Thailand

This study investigated some aspects of the reproductive biology of male and female greater bandicoot rats,Bandicota indica,in southern Thailand from September 2004 to September 2006. In females,body,uterine and preputial gland weights,occurrences of pregnancies and placental scars,and in males,testicalar weights and histology,and sizes of accessory sex glands,were recorded. Pregnancies occurred predominantly,but not exclusively,in the wet season,with a higher incidence pregnancies in the second,than in the first,dry season. Uterine and preputial gland weights tended to be lower in the first,but not the second dry season,with placental scars occurring at all times of year. Males tended to have heavier testes in the wet season but some seminiferous tubules contained sperm even in the dry season. Seminal vesicles,but not prostates and preputial glands,tended to be heavier in animals in the wet season. We conclude that the greater bandieoot rat in southern Thailand shows maximal reproductive activity in the wet season with some reproductive activity,albeit variable from year to year,occurring in the dry season depending upon environmental conditions. This study has also shown that females,as well as males,have large preputial glands,and that males invariably have small testes regardless of the time of year. These observations suggest a similar timing of reproduction,but a different breeding biology and perhaps social organisation,from that of the sympatric ricefield rat,Rattus argentiventer.     

Isolation of quinic acid derivatives and flavonoids from the aerial parts of Lactuca indica L. and their hepatoprotective activity in vitro

In our continuing study of biologically active compounds from Korean medicinal plants, we investigated the hepatoprotective constituents of the aerial parts of Lactuca indica L. (Compositae), since the methanolic extract of L. indica has hepatoprotective activity against hepatitis B virus (HBV) production. The bioactivity-guided separation of the methanolic extract of the aerial parts of L. indica resulted in the isolation of seven quinic acid derivatives (1, 3–4, 6, and 10–12), along with five flavonoids (2, 5, and 7–9). All the isolated compounds were evaluated for hepatoprotective activity by the HBV assay in vitro. In the human HBV-transfected liver cell line HepG2.2.15, all the compounds except 2 and 5 effectively reduced HBV DNA level in the release of mature HBV particles from HepG2.2.15 cultivation. Of the ten active compounds, treatment with 1, 3, and 12 led to significant reduction in the extracellular HBV DNA level, suggesting that they could be potent phytochemical agents against hepatitis B virus.     

Inheritance of resistance to anti-microtubule dinitroaniline herbicides in an “intermediate” resistant biotype of Eleusine indica (Poaceae)

Inheritance of resistance to the anti-microtubule dinitroaniline herbicides was investigated in a goosegrass biotype displaying an intermediate level of resistance (I). Reciprocal crosses were made between the I biotype and previously characterized susceptible (S) or resistant (R) biotypes. Eight F₁ hybrids were identified, and F₂ populations were produced by selfing. The dinitroaniline-herbicide response phenotype (DRP) of F₁ plants, and F₂ seedlings was determined using a root-growth bioassay. The DRP of F₁ plants of S × I was “susceptible” (i.e., identical to the S parental plants), and the DRP of F₁ plants of I × R was “intermediate” (i.e., identical to the I parental plants). Nonparental phenotypes were not observed in F₁ plants. Results indicated susceptibility to be dominant over intermediate resistance and intermediate resistance to be dominant over high resistance. Analysis of reciprocal crosses ruled out any role for cytoplasmic inheritance. When treated at the discriminating concentration (e.g., 0.28 ppm oryzalin), F₂ seedlings of S × I were classified as either S or I phenotype, and F₂ seedlings of I × R were classified as either I or R phenotype. Again, nonparental phenotypes were not observed. The 3:1 (S:I or I:R) segregation ratios in F₂ seedlings were consistent across all eight F₂ families. The results show that dinitroaniline herbicide resistance in the I biotype of goosegrass is inherited as a single, nuclear gene. Furthermore, it suggests that dinitroaniline resistance in goosegrass is controlled by three alleles at a single locus (i.e., Drp-S, Drp-i, and Drp-r).     

Thermal Hardening: A New Seed Vigor Enhancement Tool in Rice

In a laboratory study, indica and japonica rice (Oryza sativa L.) seeds were exposed to thermal hardening (heating followed by chilling followed by heating; chilling followed by heating followed by chilling; heating followed by chilling or chilling followed by heating). In indica rice, heating followed by chilling followed by heating resulted in decreased mean germination time, time to start germination, electrical conductivity of seed leachates, and time to 50% germination, as well as increased germination index, energy of germination, radicle and plumule length, root length, root/shoot ratio, root fresh and dry weight, radicle and plumule growth rate, and shoot fresh weight. In japonica rice, chilling followed by heating followed by chilling performed better than all other treatments, including control.     

籼稻标记性状等基因系的构建

选用涉及水稻(Oryza sativa L.)全部12条染色体的、表现简单遗传且易于识别的形态标记材料27份,以早籼品种浙辐802为轮回亲本,经10余次回交,转育成一套籼型标记等基因系.在此基础上,对同一染色体上的标记进行聚合,育成了15份双标记等基因系.该套材料除所带标记性状外,生育期、株高、分蘖力和穗子大小等主要农艺性性状与轮回亲本基本相仿.     

籼稻品种地谷抗稻瘟病基因的遗传

籼稻地谷是我国杂效裟育种上重要的稻瘟病抗源之一。利用我国稻区的稻瘟病菌系ＺＢ１３和ＺＢ１５对地谷与感病品种江南香糯的杂效Ｆ１、Ｆ２和Ｂ１Ｆ１群体,以及地谷与感病品种丽江新团黑谷、冈４６Ｂ和８９８７的Ｆ２群体进行接种鉴定,根据抗病性的分离确认地谷对ＺＢ１３和ＺＢ１５的抗性受显性基因控制。利用菌系ＺＢ１３接种地谷和１０个具有已知抗病基因的鉴别品种及其杂交Ｆ１和Ｆ２群体,进一步证明了地谷的抗温性受１对显