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121.
122.
南方鲇的营养学研究:饲料中大豆蛋白水平对消化率及摄食率的影响 总被引:14,自引:0,他引:14
以23.78±0.09g的南方鲇为实验对象,以Cr2O3作为测定饲料消化率的指示物,以大豆蛋白分别替代0%、13%、26%、39%、52%和65%的鱼粉蛋白,配制成6种等氮(粗蛋白48%)、等能(总能20KJ/g)的饲料,用于探讨饲料中大豆蛋白替代鱼粉蛋白的比例对南方鲇消化率及摄食率的影响。实验在27.5±0.02℃水温条件下进行6周,溶氧维持在5mg/L以上,光制为14L∶10D。结果表明,饲料中不同比例的鱼粉蛋白与大豆蛋白对南方鲇的消化率及摄食率均存在显著影响(P<0.05)。其中南方鲇对于物质、蛋白质、脂肪和能量的消化率随着大豆蛋白替代率的提高而逐步下降,当替代量为65%时,其消化率显著低于其余各组(P<0.05)。而南方鲇的摄食率均随着饲料中大豆粉添加量的升高而升高,当大豆蛋白替代鱼粉蛋白超过39%时,摄食率显著高于其余各组(P<0.05)。通过分析认为,消化率是限制南方鲇利用大豆粉的重要因素,而摄食率不是影响其利用率的主要原因。 相似文献
123.
大豆SSR技术研究进展 总被引:18,自引:0,他引:18
微卫星DNA是重复单位少于 6个核苷酸的简单重复序列。在大部分真核细胞的基因组中有着广泛分布 ,呈孟德尔式遗传。以此为基础发展起来的SSR标记是一种共显性分子标记 ,遗传多态性丰富。本文着重介绍近年来SSR技术应用在大豆遗传图谱构建、基因研究、品种鉴定和分子标记辅助育种等方面取得的进展 ,并初步预测该方法在大豆研究中的发展方向。 相似文献
124.
J. M. Lee D. Grant C. Eduardo Vallejos R. C. Shoemaker 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):765-773
Analysis of molecular linkage groups within the soybean (Glycine max L. Merr.) genome reveals many homologous regions, reflecting the ancient polyploidy of soybean. The fragmented arrangement
of the duplicated regions suggests that extensive rearrangements, as well as additional duplications, have occurred since
the initial polyploidization event. In this study we used comparisons between homoeologous regions in soybean, and the homologous
regions in the related diploids Phaseolus vulgaris and Vigna radiata, to elucidate the evolutionary history of the three legume genomes. Our results show that there is not only conservation of
large regions of the genomes but that these conserved linkage blocks are also represented twice in the soybean genome. To
gain a better understanding of the process of genome evolution in dicots, molecular comparisons have been extended to another
well-studied species, Arabidopsis thaliana. Interestingly, the conserved regions we identified in the legume species are also relatively conserved in Arabidopsis. Our
results suggest that there is conservation of blocks of DNA between species as distantly related as legumes and brassicas,
representing 90 million years of divergence. We also present evidence for an additional, presumably earlier, genome duplication
in soybean. These duplicated regions were only recognized by using Arabidopsis as a ’bridging’ species in the genome comparisons.
Received: 10 October 2000 / Accepted: 13 January 2001 相似文献
125.
M. J. Iqbal K. Meksem V. N. Njiti My. A. Kassem D. A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(2-3):187-192
Resistance to the sudden-death syndrome (SDS) of soybean (Glycine max L. Merr.), caused by Fusarium solani f. sp. glycines, is controlled by a number of quantitatively inherited loci (QTLs). Forrest showed a strong field resistance to SDS while
Essex is susceptible to SDS. A population of 100 recombinant inbred lines (RILs) derived from a cross of Essex × Forrest was
used to map the loci effecting resistance to SDS using phenotypic data obtained from six environments. Six loci involved in
resistance to SDS were identified in this population. Four of the QTLs identified by BARC-Satt214 (P = 0.0001, R2= 24.1%), BARC-Satt309 (P = 0.0001, R2 = 16.3), BARC-Satt570 (P = 0.0001, R2 = 19.2%) and a random amplified polymorphic DNA (RAPD) marker OEO21000 (P = 0.0031, R2=12.6) were located on linkage group (LG) G (Satt309 and OEO21000 were previously reported). Jointly the four QTLs on LG G explained 50% of the variation in SDS disease incidence (DI). All
the QTLs on LG G derived the beneficial allele from Forrest. Two QTLs, BARC-Satt371 (P = 0.0019, R2 = 12%) on LG C2 (previously reported) and BARC-Satt354 (P = 0.0015, R2 = 11.5%) on LG I, derived their beneficial allele from Essex and jointly explained about 40% of the variation in SDS DI.
Two-way and multi-way interactions indicated that gene action was additive among the loci underlying resistance to SDS. These
results suggest that cultivars with durable resistance to SDS can be developed via gene pyramiding.
Received: 19 January 2000 / Accepted: 30 April 2000 相似文献
126.
’Forrest’ resistance to the soybean cyst nematode is bigenic: saturation mapping of the Rhg1and Rhg4 loci 总被引:1,自引:0,他引:1
K. Meksem P. Pantazopoulos V.N. Njiti L.D. Hyten P. R. Arelli D. A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):710-717
Field resistance to cyst nematode (SCN) race 3 (Heterodera glycines I.) in soybean [Glycine max (L.) Merr.] cv ’Forrest’ is conditioned by two QTLs: the underlying genes are presumed to include Rhg1 on linkage group G and Rhg4 on linkage group A2. A population of recombinant inbred lines (RILs) and two populations of near-isogenic lines (NILs) derived
from a cross of Forrest×Essex were used to map the loci affecting resistance to SCN. Bulked segregant analysis, with 512 AFLP
primer combinations and microsatellite markers, produced a high-density genetic map for the intervals carrying Rhg1 and Rhg4. The two QTLs involved in resistance to SCN were strongly associated with the AFLP marker EATGMCGA87 (P=0.0001, R2=24.5%) on linkage group G, and the AFLP marker ECCGMAAC405 (P=0.0001, R2 =26.2%) on linkage group A2. Two- way analysis of variance showed epistasic interaction (P=0.0001, R2 =16%) between the two loci controlling SCN resistance in Essex×Forrest recombinant inbred lines. Considering the two loci
as qualitative genes and the resistance as female index FI <5%, jointly the two loci explained over 98% of the resistance.
The locations of the two QTLs were confirmed in the NILs populations. Therefore SCN resistance in Forrest×Essex is bigenic.
High-efficiency marker-assisted selection can be performed using the markers to develop cultivars with stable resistance to
SCN.
Received: 5 November 2000 / Accepted: 23 January 2001 相似文献
127.
生防菌AS818抗药性标记标在大豆根限定殖 总被引:7,自引:2,他引:5
通过60Coγ-射线(1.0×104rad)对生防菌株链霉菌AS818孢子悬液(106/mL)进行诱变,得到抗链霉素(>50μg/mL)突变株5株.经诱导,RL-4抗链霉素水平达到10μg/mL.标记株RL-4在1%水琼脂(WA)和无菌土中培养的大豆根际定殖趋势有所不同.RL-4在1%WA培养的大豆根表的定殖量呈逐步上升趋势.无菌土中种植的大豆根际和根表的检测表明RL-4可在无菌土中大豆根际短期定殖,在根际第1周数量降低了100倍,以后数量开始逐渐上升,第3周达到高峰,数量比第1周增加了3个数量级,但在第4周其数量又开始下降;在根表RL-4数量逐步下降,到第4周已检测不到RL-4的存在.组织印记法检测发现标记株RL-4可以在无菌培养的大豆根表定殖并沿根分布,但却不能定殖于根内. 相似文献
128.
脱乙酰壳多糖处理增加人参细胞皂苷的累积和皂苷合成关键酶基因的转录 总被引:2,自引:0,他引:2
脱乙酰壳多糖处理可以诱导人参细胞产生H2 O2 ,增加人参皂苷的累积 ,提高鲨烯合酶 (squalenesynthase,GSS)与鲨烯环氧酶 (squaleneepoxidase,GSE)基因的转录水平。质膜NADPH氧化酶的抑制剂DPI,H2 O2 的淬灭剂DMTU与DHC可以抑制脱乙酰壳多糖的这些效应 ,暗示脱乙酰壳多糖可以活化质膜NADPH氧化酶而产生H2 O2 ,H2 O2 进而作为第二信使诱导gss与gse基因转录以及皂苷的合成。质膜钙通道抑制剂LaCl3与内质网钙通道抑制剂RR ,以及蛋白激酶抑制剂K2 5 2a都能削弱脱乙酰壳多糖促进皂苷积累和gss、gse转录的效应 ,说明胞内Ca2 浓度的升高与蛋白质磷酸化都参与了脱乙酰壳多糖诱导的gss、gse的转录以及皂苷的合成 相似文献
129.
根据灰色局势决策原理,利用目标赋权获得加权局势决策方法,对1996—1997年山东省大豆新品种区域试验结果进行分析,综合14个主要性状指标,排出各个品种的优劣,结果与生产实际一致。认为这是一种较全面、较合理的综合评价大豆品种优劣的方法。 相似文献
130.
The fungi, Hirsutella rhossiliensis and Hirsutella minnesotensis, are two endoparasites of second-stage juveniles (J2) of the soybean cyst nematode (SCN), Heterodera glycines. The objective of this study was to screen for effective fungal isolates to control the nematode in laboratory and greenhouse assays. A total of 93 isolates of H. rhossiliensis and 25 isolates of H. minnesotensis were evaluated for parasitism of SCN J2 on cornmeal agar. Percentage of SCN J2 parasitized by the fungi varied among the fungal isolates. Most H. rhossiliensis isolates parasitized a high percentage of J2. The isolates of H. rhossiliensis obtained from bacteria-feeding nematodes, however, generally did not parasitize J2 on agar. H. minnesotensis parasitized fewer J2 on agar than did H. rhossiliensis . Forty isolates of H. rhossiliensis and four isolates of H. minnesotensis that parasitized a high percentage of J2 on agar were evaluated for their biocontrol potential in soil treated with microwave heating. Most isolates selected from the agar assay also parasitized a high percentage of J2 in the soil but there was variation among isolates. Pathogenicity of 14 isolates of H. rhossiliensis and four isolates of H. minnesotensis to the SCN was also investigated in the greenhouse using untreated field soil. Most isolates of H. rhossiliensis reduced SCN population density and increased plant growth when compared with 1% corn-grits control (culture media). One isolate (OWVT-1) of H. rhossiliensis reduced the SCN egg density by 95% and J2 density by 98% when compared with the control. Isolates of H. minnesotensis, however, neither reduced SCN density nor increased plant growth in the greenhouse. 相似文献