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21.
【目的】分析黄瓜基因组中与叶酸合成代谢相关的基因数量、定位以及表达特征,对关键酶基因进行生物信息学分析与克隆,旨在为黄瓜叶酸合成调控研究奠定基础。【方法】根据已报道的拟南芥叶酸合成相关基因,利用黄瓜基因组数据库中9930_V3版本进行BLAST比对。利用MapChart绘制黄瓜染色体物理图谱并对基因定位。利用qRT-PCR分析这些基因在黄瓜果实发育不同时期和不同材料中的表达量。通过MEGA、WebLOGO、ExPASy等工具对关键酶基因进行生物信息学分析。通过PCR扩增对关键酶基因进行克隆,并测序分析基因的序列差异。【结果】同源比对获得19个黄瓜叶酸代谢相关基因,这些基因不均匀分布在黄瓜7条染色体上,且以Chr.4和Chr.5上分布最多。通过对其中11个调控叶酸合成的基因在测序黄瓜9930果实发育不同时期以及果实叶酸含量高低差异显著的2份材料的表达量分析,发现CsFPGSCsHPPK/CsDHPSCsDHNA 3个基因与果实叶酸含量变化趋势完全一致;CsADCSCsADCLCsDHNACsHPPK/CsDHFS、CsFPGS、CsDHFS等基因的表达量在2份材料中具有显著差异。通过对2个调控叶酸合成限速步骤的关键酶基因CsGCHICsADCS的蛋白序列及蛋白结构域分析,发现各物种中CsGCHI的同源基因均具有2个GTP_cyclohydroI结构域;CsADCS的同源基因均具有2个GATase结构域、1个Anth_synt_I_N结构域和1个Chorismate_bind结构域。它们在不同物种中高度保守,进化树分析亲缘关系近的物种聚类到一起。分别扩增黄瓜果实低叶酸含量自交系65G和高叶酸含量自交系02245中CsGCHICsADCS的同源基因,序列分析表明CsaV3_1G041250全长为3 012 bp,CDS序列长度为1 413 bp,3个SNP位点的突变导致了氨基酸序列的变异;CsaV3_7G026240全长为3 047 bp,CDS长度1 407 bp,序列无变异;CsaV3_5G036360全长7 941 bp,CDS序列长度为2 706 bp,序列无变异。【结论】鉴定出19个不均匀分布在7条染色体上的黄瓜叶酸代谢相关基因,基因CsFPGSCsHPPK/CsDHPSCsDHNACsADCS是影响黄瓜果实叶酸含量变化、导致叶酸含量高低显著差异的关键基因,调控叶酸合成限速步骤的关键酶基因GCHIADCS功能相对保守,CsGCHI在65G、02245中有3个SNP位点的突变导致了氨基酸序列的差异。  相似文献   
22.
硅是地壳内含量第二丰富的元素。近年来,人们开始探索硅的纳米材料在农业领域的运用。为更好地将二氧化硅纳米颗粒应用于园艺植物生产,以黄瓜栽培品种新唐山秋瓜(Cucumissativuscv."QiuguaofNew Tangshan")为材料,采用盆栽的方式研究不同施入量下(0、5、10和20m L)浓度为30%的二氧化硅溶液对黄瓜根系解剖结构、根毛形成、黄瓜叶片光合色素含量、叶绿素荧光参数以及气体交换的影响。结果表明,二氧化硅纳米颗粒对黄瓜的根系解剖结构并没有显著的影响,但对根毛形成的影响较大,在每盆20m L二氧化硅溶液条件下的根毛密度最高。施入不同量的二氧化硅溶液对黄瓜叶片光合色素含量均有提高但并不明显,且在较低施入浓度下,光合作用机制得到一定的提高。黄瓜叶片的净光合速率随着二氧化硅施入量的增加逐渐增加,但施入量对蒸腾速率的影响不明显。综上,二氧化硅纳米颗粒通过促进根毛形成以及提高净光合速率能够提高植物的生长机理,进而促进植物生长和产量的提高,将其运用于农业生产及园艺作物生产上具有广阔前景。  相似文献   
23.
全球变暖会对舟山沿岸上升流的驱动机制产生深远影响,继而作用于海域内的生态环境及渔业资源发生的变迁。使用三维海洋数值模型FVCOM,模拟研究了热通量、风场等气候环境因子变化下舟山沿岸上升流区夏季水动力及环境因子的分布特征。通过引入跃变检验方法来评估全球变暖对过去三十多年来舟山及其邻近海域的夏季海表温度的影响,发现在2016年前后发生了明显的跃变,跃变后海表温度相对于跃变前升高了约1 °C;热通量分析结果显示春季云量减小,短波辐射增加导致的海水热含量增加是夏季海水升温的重要原因;风速的时空变化表明舟山海域7月风速在近几十年有减弱的趋势。通过构建气候环境因子变化的敏感性数值模型实验探究了舟山沿岸上升流水动力的演变机制,结果表明海气热通量增加导致的表层海水吸热及平流热输运增加引起的海水层化加强会使得底层海水不易抬升;夏季风应力的减弱削弱了长江冲淡水低盐水舌的离岸扩展,导致上升流区上层海水的层化减弱,从而加强中下层海水向岸爬升,增加沿岸上升流的强度。  相似文献   
24.

BACKGROUND

Ecballium elaterium (common name: squirting cucumber) is an emerging weed problem in hedgerow or superintensive olive groves under no tillage. It colonizes the inter-row area infesting the natural or sown cover crops, and is considered a hard-to-control weed. Research in other woody crops has shown E. elaterium has a patchy distribution, which makes this weed susceptible to design a site-specific control strategy only addressed to E. elaterium patches. Therefore, the aim of this work was to develop a methodology based on the analysis of imagery acquired with an uncrewed aerial vehicle (UAV) to detect and map E. elaterium infestations in hedgerow olive orchards.

RESULTS

The study was conducted in two superintensive olive orchards, and the images were taken using a UAV equipped with an RGB sensor. Flights were conducted on two dates: in May, when there were various weeds infesting the orchard, and in September, when E. elaterium was the only infesting weed. UAV-orthomosaics in the first scenario were classified using random forest models, and the orthomosaics from September with E. elaterium as the only weed, were analyzed using an unsupervised algorithm. In both cases, the overall accuracies were over 0.85, and the producer's accuracies for E. elaterium ranged between 0.74 and 1.00.

CONCLUSION

These results allow the design of a site-specific and efficient herbicide control protocol which would represent a step forward in sustainable weed management. The development of these algorithms in free and open-source software fosters their application in small and medium farms. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
25.
<正>西番莲(Passiflora edulis Sims.)是热带亚热带地区重要经济作物,我国福建、广东、广西、海南等地广泛种植[1]。调查发现,我国南方多地西番莲花叶病为害严重,症状表现为叶片花叶、黄化、斑驳、畸形,甚至整株褪绿,严重影响西番莲的产量和品质。已报道能引起西番莲花叶症状的病毒有:黄瓜花叶病毒属(Cucumovirus)的黄瓜花叶病毒(cucumber mosaic virus, CMV),  相似文献   
26.
27.
Although the sea otter (Enhydra lutris) is a complete aquatic species, spending its entire life in the ocean, it has been considered morphologically to be a semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology and functional adaptations of E. lutris in comparison to other Mustelidae species. We compared muscle mass and bone measurements of five Mustelidae species: the sea otter, Eurasian river otter (Lutra lutra), American mink (Neovison vison), Japanese weasel (Mustela itatsi) and Siberian weasel (M. sibirica). In comparison with the other 4 species, E. lutris possessed significantly larger gluteus, popliteus and peroneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle may act as a medial rotator of the crus, and the peroneus muscle may act as an abductor of the fifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscle of E. lutris were fused with those of the tensor fasciae latae muscle and gluteofemoralis muscles, and they may play a role in femur abduction. These results suggest that E. lutris uses the abducted femur, medially rotated crus, eversion of the ankle and abducted fifth digit or extended interdigital web as a powerful propulsion generator. Therefore, we conclude that E. lutris is a complete aquatic animal, possessing differences in the proportions of the hindlimb muscles compared with those in other semi-aquatic and terrestrial mustelids.  相似文献   
28.
海堤边坡几种树种适宜性评价   总被引:1,自引:0,他引:1  
为了给海堤绿化及沿海防护林的营建提供科学依据,通过对海堤边坡水分、盐分以及大气等立地因子的综合研究分析,结合海堤边坡造林试验,对杂交柳、紫穗槐、黄金条、刺槐、楝树、铅笔柏6个树种的生长适宜性作出了评价,研究结果表明:(1)海堤边坡土壤属于中度到强度盐渍化土且土壤含水率季节变化大,其中海雾、海风也是海堤立地条件中非常重要...  相似文献   
29.
Sea urchins produce high‐energy, membrane‐bound fecal pellets that contain residual nutrients and large quantities of microbiota. These egesta are readily consumed by the shrimp, Litopenaeus vannamei. Egesta of the sea urchin, Lytechinus variegatus, were evaluated as a feed supplement or total replacement for a commercial shrimp diet. Shrimp were stocked at 0.49 g ± 0.06 g initial body weight and housed individually in 2.8‐L tanks in a commercial recirculating zebrafish system. Shrimp were assigned to one of six diets: commercial shrimp feed, reference sea urchin feed, collected dried sea urchin egesta, collected wet sea urchin egesta, half ration of shrimp feed and half collected wet sea urchin egesta, and egesta naturally produced by two sea urchins in polyculture. Equivalent dry matter amounts of each diet were proffered to shrimp in each treatment twice daily, except for those that had complete access to natural egesta excreted by sea urchins in polyculture. Sea urchins were proffered a reference sea urchin feed at 2% body weight daily. After 27 days, shrimp proffered collected dried or wet egesta did not differ significantly in percent weight gain and showed the lowest weight gain. The percent weight gain of shrimp fed the commercial shrimp diet did not differ significantly from that of the shrimp fed half commercial shrimp diet and half egesta. The highest weight gain was recorded for those shrimp that consumed the untouched egesta produced by sea urchins in polyculture. These data suggest that consumed egesta have noteworthy nutritional value and therefore would be beneficial to the culture of extractive species in an integrated multitrophic aquaculture system.  相似文献   
30.
To investigate the effects of family, stocking density, and their interaction on mortality, growth rate, and size dispersal in the sea urchin Strongylocentrotus intermedius, 1,440 juveniles from six full‐sib families were exposed to three stocking densities, that is, low stocking density (LD), middle stocking density (MD), and high stocking density (HD), and reared for 10 months in sea‐based suspended cages. The results demonstrated significant family effects on cumulative mortality rate (CMR); specific growth rate for test diameter (SGR for TD); specific growth rate for body weight (SGR for BW); coefficient of variation for body weight at the 10th month (CV for BW10); and significant stocking density effects on SGR for TD, SGR for BW, and CV for BW10. Statistically significant family by stocking density interaction was only found in SGR for TD. A certain degree of family‐ranking inversions occurred in SGR for TD. The present study provides evidence for the existence of family by stocking density interaction on the growth rate of test diameter in the family selection for S. intermedius. More attention should be paid to this interaction effect to select correct parents in S. intermedius.  相似文献   
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