• The Application of Somaclonal Variation in Early Maturity,High Yield and High Quality Improvement in Wheat

    Yield characters, maturity and grain protein content of somaclones derived both from immature embryo of cultivar 77(2)-Spring and single-cell culture of cultivar NE7742 in vitro were studied and the wide variation was found. Somaclones with maturity 8 days earlier than or the same as CK NE 7742 (high yield, early maturity and high quality), combining with high quality (grain protein content 15.5% - 18%) and high yield (the same as 7724 or higher) have been found and selected and now multiplied for 8 generations. The results of cultivar comparison trial in 1995 showed that several somaclones (the yields were significantly higher than CK DN120) could be used directly in wheat production. The studies confirmed that somaclonal variation is one of the effective ways for early maturity, high-yielding and high-quality improvement in wheat.

    1996年02期 81-87页 [查看摘要][在线阅读][下载 259k]
    [下载次数:16 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:21 ]
  • Selection Effects of Soil Fertility on the Progenies of Soybean Crosses

    The F2, F3, families and F4 lines of six soybean crosses, were selected successively under high-and low - fertility sites with the relection objective of high yield and the method of pedigree was used. Two best F4 - derived lines were chosen from each of the six crosses under both high-and low-fertility for use in this study. In 1995, the total 24 lines were tested in high, medium and low fertility sites with the same experimental design (CRB) to study the selcctoin effects of high and low - fertility. The results suggested that high- and low-fertility had different selection effects. High fertility was more effective for selecting lines, which had higher yield under high-fertility and lower yield under low-fertility; low-fertility was better for selecting lines, which had higher yield under low-fertility and lower yield under low-fertility, and high fertility was somewhat better than low fertility for selecting lines, which had higher yield under both high and low-fertility. It revealed that the lines selec

    1996年02期 88-93页 [查看摘要][在线阅读][下载 198k]
    [下载次数:15 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:27 ]
  • The Eco-Geographical Distribution of Chemi-cal Composition of Soybean Seeds

    The expression of protein and oil content of soybean seeds in worldwide was studied. The results shown that: Latitude and year's weather conditions affected protein content of soybean seeds importantly. Elevation affected oil content significantly. There was important difference in protein / oil content among different eco - geographical regions. The zone, in which there was the highest content of protein / oil, was that one with latitude from 0°to 20°59′ . And in this zone, there were different elevation regions, in which protein or oil content was the highest. For high pro-tein, it was the elevation region with 500 - 1000 m; for oil, it was 0~ 500 m. Protein / oil content was also different among different years. However, the changing range among years in Tropical and Subtropical regions was smaller than that in Temperate Regions. The relationship between protein / oil content and latitude, elevation or soil pH in the regions outside the Tropic of concerned a

    1996年02期 94-102页 [查看摘要][在线阅读][下载 979k]
    [下载次数:5 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:20 ]
  • Estimating Combining Ability of 4x-2x Crosses in Cultivated Potatoes

    Progenies derived from crosses between Solarium tuberosum and 2n pollen-Producing diploid hybrids, exhibit obvious hybrid vigor. The 2n pollen-producing clone can act as a bridge in crossing S. tuberosum and S. andigena with S. phureja. Populations from 4x-2x crosses show more unifomity and less segregation compared with that of 4x-4x crosses. The parent-offspring correlation for the traits, starch content and tuber number, is significant at 0.01 level. The regrssion equations are Y (mp-F1)=1.0 + 1.2x and Y (mp - F1) = 5.3 + 0.8x, respectively. The 2n pollen-producing clones play an impotant role in increasing tuber stach content. Estimates of the combining ability for the main yield components indicate that additive effect prodominatcs for such trais as plot yield, tuber weight per plant and starch content, whereas both additive and non-additive effects lay equal stress on mean tuber weight and non-additive effect is important for tuber number. In general, non-additive effect appears to be important in

    1996年02期 103-109页 [查看摘要][在线阅读][下载 243k]
    [下载次数:5 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:24 ]
  • Effects of Fertilizing Materials on Rapidly Available-N in Black Soil in Songnen Plain

    The analyses on the mathematical models of the long- term location test in black soil in Song-nen Plain shows that farm manure and chemical fertilizers make great contribution to rapidly available-N in soil, while stalk makes less contribution. The most optimal pattern of fertilizing materials is 28 t / ha of farm manure, 630 kg / ha chemical fertilizers and 2.41 / ha of stalk.

    1996年02期 110-116页 [查看摘要][在线阅读][下载 208k]
    [下载次数:14 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:16 ]
  • Preliminary Studies on Induced Resistance of Cucumber to Downy Mildew

    1 mL of sporangial suspensions (5 x 10 5spporangia per milliliter) of Pseudoperonospora cubensis was droplet-inoculated on the surface of the second leaf of the plant grown in greenhouse ( inducing inoculatoin), then the lower surfaces of the third, the forth and the fifth leaves were uniformly sprayed with inoculum of the same fungi (5 x 10 4sporangia per milliliter, about 5 mL per plant) every 3 days interval (challenge inoculation). Plants were moistened at 18- 22 C for 18 h, then kept at room temperature (24 - 28 C) and supplemented with cool-white fluorescent lights. All three challenge leaves were collected after 7 days of challenge to measure the amount of sporulation and area of necrosis. Plants prior inoculated with P. cubensis were protected 38% (based on the area of necrosis) against disaesc caused by subsequent foliar challenge with the pathogen. Protective action was about 12% after 3 days, and maintained this level until 9 days, suddenly reached 34% after 12 days, and came to a maximum after 15

    1996年02期 117-120页 [查看摘要][在线阅读][下载 125k]
    [下载次数:20 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:15 ]
  • Regulation of Development and Endogenous Polyamine Level in Chinese Cabbage (B. Campestris ssp. Pekinensis)

    The endogenous polyamine levels were tested at every developmental stage in different ecotypes of the Chinese cabbage. The results showed that polyamincs (PAs) were decreased in the process of flower bud initiation and fornfation, but the floral stem formation and elongation were accompied by PAs increase. The level of Spm was related to the bolting date of Chinese cabbage. During the inducing of flower bud initiation and elongation of floral stem, and the changes of Spm were reversed between early bolting date and late bolting cultivars, but they have the same requirment for Spd for the starting of flower bud initiation and the starting of bolting. The level of Spd changed little during entire developmental stage for early bolting cultivars, but a lot for late bolting cultivars. The time that the highest level of Put appeared is related to the bolting date of Chinese cabbage.

    1996年02期 121-125页 [查看摘要][在线阅读][下载 158k]
    [下载次数:11 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:14 ]
  • Assessment of Negative Training on the Use of Cubicle Beds by Heifers

    40 in-calf heifers were observed to examine the effect of timbers placing in passage area on their use of cubicle beds. Prior to the experiment preliminary observation was taken on these 40 heifers and they were divided into two even groups (cubicle user(or control) group versus cubicle refusal (or experimental) group by whether they properly used the cubicle beds or not. The timbers were placed in passage and feeding areas for the cubicle refusal group to force the animls to lie in the cubicle beds. The results of this experiment showed that feeding behaviour was unaffected by the presence of the timbers, but lying acitvity was about 8% higher for the experimental group, which led to a mean of almost 2 hours longer lying time over 24 h. After the timbers were removed, there was a significant decline in lying by the experimental group. The diurnal pattern of lying behaviour in cubicles indicated that the major effect on lying activity exerted by the presence of the timbers was seen during midnight to 10:00 a

    1996年02期 126-131页 [查看摘要][在线阅读][下载 195k]
    [下载次数:4 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:24 ]
  • Effect of Bospro on High and Mid-to-Low Milk Yielding Chinese-Holstein Cow

    A total of 90 cows from two farms (farm A 30 cows, farm B 60 cows) were used to study the effect of Bospro on milk production, milk quality and subclinical mastitis incidence. The cows in the test group were supplied with 20 g of Bospro per head per day and meanwhile, the percentage of milk fat, protein and lactose and moisture of the milk samples were analysed. The results showed that the milk yield of both high production and mid-to-low milk producting cows increased by 3.3% to 5.3% respectively compared with their control group of cows, but there was no changes on the milk content between the treated and the control cows. The treated cows also showed an increased body weight (P>0.05) and significantly reduced incidence of mastitis, as Compared with that of the control group. The experiment dcmonstrats that Bospro can increase milk yield, but not at the expense of milk quality and body weight.

    1996年02期 132-138页 [查看摘要][在线阅读][下载 190k]
    [下载次数:18 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:19 ]
  • Alpase of Follicles during the Period before and after Ovulation in Superovulated Rabbits

    The Alpas of follicles was studied systematically during the period before and after ovulation in superovulated rabbits. The locations and changes of follicular Alpase varied with the four kinds of physiological status before and after ovulation. Alpasc activity was the highest at oestrus and started to drop at the beginning of ovulation, then it increased 15 h later and decreased slightly 39 h afterwards the beginning of ovulation. Alpase was found on the follicular basement membrane at oestrus. The synthesis of fiber in fibcrblasts was connected with Alpasc activity.

    1996年02期 139-144页 [查看摘要][在线阅读][下载 715k]
    [下载次数:5 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:22 ]
  • Proliferative Functions of Hematopoietic Progeritors in Bone Marrow of Chickens Infected with Cav

    Development of marrow colony forming unit erythrocytic (CFU-E), colony forming unit granulocytic and macrophagic (CFU-GM) and colony forming unit fibroblastic (CPU桭) of chicken anemia virus (CAV) infection were examined by using In vitro culture techniques of hematopoietic progenitor cells. Chicks were inoculated intraperitoneally and intramuscularly with CAV at one day of age. The results showed that CAV inhibited proliferation of CFU-E and CFU-GM of chick bone marrow. In vitro culture, growth of CFU-E was inhibited from day 14 to 35 postinoculation (PI), and growth of CFU-GM was greatly inhibited from 7 to 21 days PI. Growth of CFU-E and CFU-GM recovered at day 42 PI. No effect was found on growth of CFU-F of bone marrow in chicks infected CAV.

    1996年02期 145-149页 [查看摘要][在线阅读][下载 171k]
    [下载次数:3 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:30 ]
  • Research on Power Circulation in of a front Wheel Assist Tractor

    Base on dynamic analysis for a Front Wheel Assist (FWA) tractor, a method of calculating and analyzing on the critical angle of steering for a FWA tractor is described in this paper. The mathematical model is also established here. The critical steering angle which is a important parameter affecting the steering performance for a FWA tractor is defined in the article.

    1996年02期 150-155页 [查看摘要][在线阅读][下载 152k]
    [下载次数:19 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:30 ]
  • Preliminary Studies on the Production of Artificial Seeds by Encapsutating Microtubers of Potato

    The production of atificial seeds by encapsulating microtubers of potato included a series of processes. Initially, the micropropagation of adventitious buds and microtuber - inducing system should be established. Both high quality microtuber and synchronizing microtuber which have the same size were necessary for producing health potato artificial seeds. In our experiment, the optimum medium of adventitious shoot-inducing of potato Hutao, Kesi, and Favorita is DCR + 1.0 mg / kg BA+ 0.5 mg / kg IBA+ 500 mg/ kg LH; the optium medium of microtuber- inducing of Hutao and Kesi is DCR+5.0 mg/ kg BA+200 mg/ kg Lh+8% sugar, and the optium medium of microtuber -inducing of Favorita is DCR+ 5.0 mg/ kg BA+0.1 mg / kg NAA+200 mg/ kg LH+8% sugar. Microtubers of the same size were gained by selecting the synchronous microtubers. 2.0% sodium alginate was used to encapsulate the microtubers of potato to form the artificial seeds, and the concentration of Ca C12 is 4%. Phytohormone NAA promoted the germination of potato art

    1996年02期 156-159页 [查看摘要][在线阅读][下载 151k]
    [下载次数:35 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:15 ]
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