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1.
Summary The inheritance of resistance to the twospotted spider mite and of bitterness in cucumber has been studied in three sets of P1, P2, F1, F2, B11 and B12 of crosses between three bitter, resistant lines and one non-bitter, susceptible line. Resistance to the twospotted spider mite as measured by acceptance and oviposition appeared to be determined by several to many genes, which are inherited mainly in an additive fashion. Bitterness is basically governed by the gene Bi, which, contrary to earlier reports, is inherited in an intermediary way, while the expression of Bi is influenced by additively inherited intensifier genes. Whereas Bi and the bitterness intensifier genes are not related to the resistance factors acceptance and oviposition, they are related to resistance or tolerance as measured by the damage index. This relation is explained by linkage rather than by identity of the genes concerned. Changes in the test methods and breeding consequences are discussed. 相似文献
2.
葫芦素具有显著的抗癌活性,解析其生物合成途径对异源生产葫芦素具有重要意义。葫芦素首先由葫芦二烯醇（Cuol）在氧化鲨烯环化酶（OSCs）家族的葫芦二烯醇合酶（CBS）催化下生成2,3-氧化鲨烯,后者在细胞色素P450(CYP)等酶催化下氧化修饰产生葫芦素系列化合物。本研究在建立高效的根癌农杆菌（Agrobacterium tumefaciens）介导的瞬时表达体系的基础上,将雪胆（Hemsleya chinensis Cogn.）CBS基因（HcOSC6）与截短的燕麦（Avena strigosa）3-羟基-3-甲基-戊二酰辅酶A还原酶基因（tHMGR）共表达,通过不断优化烟草共表达体系,将本氏烟草（Nicotiana benthamiana）叶片中的Cuol产量从2.832 mg/g（干重）提高到9.48 mg/g（干重）。同时,将雪胆的HcCYP87D20共渗入烟草叶片,获得葫芦素生物合成的重要中间体11-羰基-20β-羟基-葫芦二烯醇。本研究结果将为葫芦素的高效异源合成提供理论依据。 相似文献
3.
O. M. B. De Ponti 《Euphytica》1980,29(2):261-265
Summary The bitter cucumber variety Improved Long Green did not differ in resistance to the twospotted spider mite from its near isogenic non-bitter mutant, the source of all non-bitter varieties. Four pairs of near isogenic bitter and non-bitter varieties gave similar results. Therefore any causal relation between bitterness and resistance is denied. 相似文献
4.
Cucurbitacin-rich extracts are phagostimulants for both male and female Luperini, but field trials reveal that males are far more attracted to them than females. The sex ratio and number of beetles killed by an application of cucurbitacin-based toxic baits was assessed at two different scales: small areas of 100 m2, and a larger area of 10,000 m2. The small area bait applications killed mostly males (95.2%), but the 1-ha treated plot showed a lower sexual bias (57% male). An earlier study indicated point sources (sticky traps) attracted only males. Results indicate that the distance attraction to bitter cucurbit extracts is almost exclusive to males, but the wide dispersal of a toxic bait based on them should promote encounter and control of both sexes within the treated area. No significant non-target effects were observed. 相似文献
5.
为明确药西瓜UDP-糖基转移酶催化葫芦素形成葫芦素配糖体的表达规律,以药西瓜品种"WM9"叶片为供试材料,采用RT-PCR技术克隆药西瓜UDP-糖基转移酶基因,并对编码蛋白进行分析。通过实时荧光定量PCR(qRT-PCR),以ACTIN为内参基因,分析获得的2个药西瓜UDP-糖基转移酶基因在不同组织器官中的表达规律。结果表明:克隆得到2个UDP-糖基转移酶基因,分别为1 546 bp和1 559 bp的cDNA全长序列,命名为UDP-E1和UDP-E2。对扩增获得的序列进行生物学信息分析,确定UDP-E1基因的完整开放阅读框(ORF)为1 314 bp,可编码氨基酸437个,理论分子量为49.02 ku,等电点为5.99,属稳定蛋白,Genbank登录号MK576125。UDP-E2基因的ORF为846 bp,可编码氨基酸281个,理论分子量为32.78 ku,等电点为5.23,属不稳定蛋白,Genbank登录号MK576126。这2个基因属于糖基转移酶超家族。UDP-E1和UDP-E2均与香瓜、黄瓜的UDP-糖基转移酶基因序列相似性最高。在各组织器官中,UDP-糖基转移酶均有表达,且在茎中表达水平最低,叶中表达水平最高。 相似文献
6.
完善甜瓜蒂质量标准并提高。采用薄层色谱法对甜瓜蒂进行定性鉴别,并采用高效液相色谱法测定葫芦素B的含量,色谱条件:Agilent HC-C18色谱柱(250 mm×4.6 mm,5μm),乙腈-0.1%磷酸溶液(60∶40)为流动相,流速为1.0 mL/min;检测波长为228 nm。结果表明,薄层色谱斑点清晰,分离度好,专属性强,重复性良好;高效液相色谱法测定葫芦素B的回归方程为:Y=1 367 962.09X+465.59,r=0.999 6,在0.0340~4.247 0 mg/mL线性关系良好;平均回收率为98.4%,RSD为1.6%。说明该研究建立的薄层色谱鉴别和高效液相色谱含量测定方法简便、快捷、结果准确、可靠,为甜瓜蒂质量标准的修订完善提供了可靠依据。 相似文献
7.
J. T. Madaure P. W. Mashela D. De Waele 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2019,69(3):235-240
Interactive effects of alternatives to methyl bromide on root-knot (Meloidogyne species) nematodes could provide information on whether to use the products combined or singularly. The objective of this study was to investigate the interactive effects of Nemarioc-AL phytonematicide, Steinernema feltiae and Trichoderma harzianum on eggs and reproductive factors of Meloidogyne incognita race 2 under greenhouse conditions. The interactive effects of Nemarioc-AL phytonematicide (N), S. feltiae (S) and T. harzianum (T) on population densities of M. incognita were examined in a 2?×?2?×?2 factorial experiment in pots filled with steam-pasteurised soil. Each tomato seedling was inoculated with 2000 eggs and second-stage juveniles (J2), with phytonematicide and biocontrol agents applied at commercial rates. At 56 days after the treatments, the second-order (N1S1T1) interaction reduced eggs and the reproductive factor (RF) in roots by 100% and 93%, respectively. Similarly, the first-order (N1S0T1) interaction reduced the two variables by 92% and 72%, respectively, whereas N1S1T0 interaction had 63% and 55% reduction effects, respectively. Nemarioc-AL phytonematicide was compatible with S. feltiae and T. harzianum and could, therefore, be used collectively to manage population densities of M. incognita. 相似文献
8.
葫芦素B对甜菜夜蛾幼虫取食和成虫产卵的影响 总被引：4，自引：0，他引：4
测定了葫芦素B对甜菜夜蛾1～3龄幼虫取食和成虫产卵的影响.结果表明,当质量浓度达到16 0 0 μg·mL-1时,葫芦素B对1龄幼虫有拒食作用,并降低其存活率,干扰作用控制指数(IIPC)为0 70 0 ;在相同质量浓度下,葫芦素B抑制成虫产卵,产卵抑制率达5 5 5 % ,IIPC为0 4 4 5 . 相似文献
9.
O. M. B. de Ponti 《Euphytica》1979,28(3):569-577
summary After crossing partially resistant varieties some lines with a markedly higher resistance level were selected. This transgression for resistance indicates a polygenic inheritance of the resistance. On the most resistant F5 lines selected, oviposition was reduced by 50 to 60% and the economic damage threshold was reached 5 to 8 weeks later than in the susceptible control. The level of acceptance was not influenced by the selection.The selection of individual F2 plants was hampered by low heritabilities, whereas the heritabilities of F3- and subsequent line means were generally high enough. Selection for higher resistance levels was attended by an unintended increase in cucurbitacin content. This is explained by linkage of genes for resistance and bitterness rather than by identity of these genes. 相似文献
10.
P. W. Mashela K. M. Pofu 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(8):743-747
Cucurbitacin-containing phytonematicides consistently reduce nematode population densities in various crops. However, there is no information on how these products affect the accumulation of essential nutrient elements in crops. The objective of this study was to determine the influence of Nemafric-BL and Nemarioc-AL phytonematicides on accumulation of essential nutrient elements in leaf tissues of green bean (Phaseolus vulgaris L.) under greenhouse conditions. Weekly application of phytonematicides each at 0%, 2%, 4%, 8%, 16% and 32%, were assessed on plant growth variables, nematode suppression and nutrient elements (Ca, K, Na, Fe, Zn) in leaf tissues of green bean at 56 days after initiating the treatments. Phytonematicide concentrations significantly (P?≤?0.05) affected nematode numbers and nutrient elements, without affecting plant growth. Calcium (R2?=?0.97), K (R2?=?0.93), Na (R2?=?0.94) and Fe (R2?=?0.91) each with increasing Nemafric-BL phytonematicide concentration exhibited positive quadratic relations. In contrast, K (R2?=?0.97) and Fe (R2?=?0.98) each with increasing Nemarioc-AL phytonematicide concentration exhibited positive quadratic relations, whereas Na (R2?=?0.92) and Zn (R2?=?0.72) each with increasing phytonematicide concentration exhibited negative quadratic relations. In conclusion, accumulation of essential nutrient elements in green bean leaf tissues and increasing phytonematicide concentrations exhibited density-dependent growth patterns prior to the eventual expression of plant growth responses. 相似文献