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71.
黄淮海平原高产田作物群体结构特征 总被引:9,自引:5,他引:4
本文利用实测资料分析了高产田作物群体结构特征。精播高产栽培麦田春季最大蘖数12×10~6/ha,群体最大叶面积指数5.5—6.0,成穗4.5—5.25×10~6/ha。传统高产栽培麦田春季最大蘖数15—18×10~6/ha,群体最大叶面积指数6.0—6.5,成穗6.0—7.5×10~6/ha。小麦营养生长与生殖生长期叶日积比,精播高产栽培麦田是1∶0.89,传统高产栽培麦田为1∶0.73。夏玉米种植密度主要受叶倾角的影响。紧凑型玉米品种的叶倾角大于65°,种植密度7.5—8.25×10~4/ha;平展型玉米品种的叶倾角小于50°,种植密度5.25—6.0×10~4/ha。 相似文献
72.
DNA probes to identify members of the Anopheles farauti complex 总被引:2,自引:0,他引:2
DNA probes have been constructed to distinguish between the members of the Anopheles farauti complex of mosquitoes known as species numbers 1, 2 and 3. Partial genomic libraries of the three known species were exposed to labelled total genomic DNA from each species. Colonies showing differential hybridization were selected for further testing. These probes were found which allow identification of the three known species: probe pAf1 (160 bp fragment) hybridizes to DNA from An. farauti nos. 1 and 2; probe pAf2 (95 bp fragment) hybridizes to DNA from An. farauti no. 2 only; and probe pAf3 (1.3 kb fragment) hybridizes strongly to DNA from An. farauti no. 3, less to no. 1 and faintly to no. 2. Increasing the stringency of hybridization reduced the cross-hybridization of probes pAf1 and pAf3. Only radioactively labelled probes were tested. Males and females and individuals from diverse habitats and localities showed the same species/probe hybridization characteristics. This technique allows faster identification of the sibling species than previous methods, and has the added advantage that it allows air-dried and alcohol stored specimens to be identified. 相似文献
73.
A survey of oligotrophic Lake Rara, the biggest lake in Nepal, was carried out from 1982 till 1984. Mean depth is 100 m, and
maximum depth is 167 m. The surface area covers 9.8 km2, and the lake contains 0.98 km3 volume of water.
Transparency was about 16 m, photoquantum yield decreased exponentially with depth below 5 m, and the extinction coefficient
was 8.3 × 10−2. The concentration of Chl.-a was in the range of 0.06–0.46 mg m−3, and total nitrogen was 18–30 μg 1−1. The whole water column was well oxygenated. Primary productivity was extremely low. It has more than 30 inflowing brooks
and one outlet. The water quality of the brooks changes drastically with their location. The pH, electrical conductivity,
and EDTA hardness in the waters from a landslide area were high. In the waters from a rich pine forest they were extremely
low.
The zooplankton consisted of two species of protozoa, five species of rotifers, two species of Cladocera, and two species
of Copepoda. The zooplankton density range was 6200–16200 individuals m−3. The minimum was on November 11th, 1983 and the maximum on August 19th, 1983. 相似文献
74.
75.
Gibberellins (GAs) A17, A19, A20, A29, A44, 2OH-GA44 (tentative) and GA29-catabolite were identified in 21-day-old seeds of Pisum sativum cv. Alaska (tall). These GAs are qualitatively similar to those in the dwarf cultivar Progress No. 9 with the exception of GA19 which does not accumulate in Progress seeds. There was no evidence for the presence of 3-hydroxylated GAs in 21 day-old Alaska seeds. Dark-grown shoots of the cultivar Alaska contein GA1, GA8, GA20, GA29, GA8-catabolite and GA29-catabolite. Dark-grown shoots of the cultivar Progress No.9 contain GA8, GA20, GA29 and GA29-catabolite, and the presence of GA1 was strongly indicated. Quantitation using GAs labelled with stable isotope showed the level of GA1 in dark-grown shoots of the two cultivars to be almost identical, whilst the levels of GA20, GA29 and GA29-catabolite were significantly lower in Alaska than in Progress No. 9. The levels of these GAs in dark-grown shoots were 102- to 103-fold less than the levels in developing seeds. The 2-epimer of GA29 is present in dark-grown-shoot extracts of both cultivars and is not thought to be an artefact.Abbreviations cv
cultivar
- GAn
gibberellin An
- GC
gas chromatography
- GC-MS
combined gas chromatographymass spectrometry
- HPLC
high-pressure liquid chromatography
- KRI
Kovats retention index
- MeTMSi
methyl ester trimethylsilyl ether 相似文献
76.
Haruki Ochi 《Environmental Biology of Fishes》1985,12(2):155-160
Synopsis Reproductive behavior of the temperate damselfish, Chromis notata, was investigated on the island of Mukaishima, Japan, almost daily during the breeding season in 1982. Both males and females
repeated reproductive cycles many times during the breeding season. Females had a strong tendency to spawn a whole clutch
on one nest during a few hours. The average number of eggs which a male gained per reproductive cycle was estimated at 38560
(480–131100 eggs). Males ordinarily cared for eggs until just prior to hatching, but abandoned more than half of the nests
with the eggs numbering less than 11568.
Contribution 207 from the Mukaishima Marine Biological Station. 相似文献
77.
78.
Masazumi Mitani 《Primates; journal of primatology》1986,27(4):397-412
Japanese monkeys often exchange the particular vocal sound, “coo,” especially when they feed or move as a group. It was considered
that the “coo” sound had no positive social meaning, perhaps because the “coo” sound network and its function were hidden
behind other behavioral observations. For identification of the vocalizer only from hearing the “coo” sound, three phonetic
values, i.e., the “fundamental,” “duration,” and “formants,” plus other characteristics were used as indices of voiceprints. The results indicated that these were effective for identifying
the vocalizer in two-thirds of the adults in the study troop which was composed of 12 adults and 16 immature members. The
“coo” sound exchange network among the troop members (adults) was drawn on the basis of the voiceprint identification. The
network showed three characteristics as follows: (1) matriarchs of the kin-groups frequently exchanged “coo” sounds with each
other; (2) the other females exchanged “coo” sounds mostly within their own kin-groups; and (3) males seldom participated
in the “coo” sound exchange. This suggests that “coo” sound exchange plays a central role for the matriarch of kin-groups
in binding each kin-group and, ultimately, in binding all members together into an organized troop. 相似文献
79.
J. S. C. Smith O. S. Smith 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,71(4):607-612
Summary Alcohol soluble seed storage proteins (zeins and alcohol soluble glutelins) of maize (Zea mays L.) were separated by reversed-phase high-performance liquid chromatography (RP-HPLC). The objectives were to assess the reproducibility of chromatographic profiles using seed of inbred lines that had been produced in different locations and years. Reproducible differences between sources were seen but these were restricted to proteins that contributed 2% or less to an inbred profile. The majority of variation (93% for peak percent area; 99.8% for elution time) was between inbreds. RP-HPLC can therefore provide distinctive phenotypic profiles that are largely characteristic of genotype. Such qualitative and quantitative data will be valuable for studies of taxonomy, evolution, genetics, and germplasm identification. 相似文献
80.
A method for characterizing nanogram quantities of poly(A)-containing messenger RNAs that have been fractionated according to size by electrophoresis through agarose gels has been developed. The mRNAs from Friend leukemia cells were identified by the protein products they encode, as determined by slicing the agarose gel and directly translating the enclosed mRNA with an extract from rabbit reticulocytes that had been treated with micrococcal nuclease. A number of parameters which affect the efficiency of translation in this system have been examined. These include the sensitivity of the in vitro translational system to RNA, the agarose concentration, the incubation temperature, and the addition of either exogeneous tRNA or RNasin. The procedure is rapid, simple, reproducible, and applicable for the fractionation and characterization of mRNAs from any source. 相似文献