Effectiveness of quantitative resistance conferred by the genetic background of pepper in the control of root‐knot nematodes and influence onto durability of Me1‐ and Me3‐resistant genes in greenhouse conditions          下载免费PDF全文

Fulgencio Sánchez‐Solana  Caridad Ros  María del Mar Guerrero  Victoriano Martínez  Carmen María Lacasa  Ana Hernández  Alain Palloix  Alfredo Lacasa 《Plant Breeding》2017,136(5):759-766

In pepper (Capsicum annuum), the major genes (R‐genes) Me1 and Me3 confer resistance against root‐knot nematodes (Meloidogyne spp.). The combination of R‐genes and quantitative resistance factors in the same genotype is considered a good breeding strategy for increasing the durability of R‐genes. To ascertain this hypothesis, five pepper inbred lines, differing in their quantitative resistance level, were combined with Me1 or Me3 genes in F₁ hybrids. The resistance of inbred lines and F₁ hybrids was evaluated in a greenhouse with soil naturally infected by M. incognita in two successive growing years. In both years, lines carrying Me3 were less infected by the nematode when combined with quantitative resistance. An increase in nematode infection was observed in the second growing year in lines carrying Me1 or Me3, independently of quantitative resistance. The infection level recorded in inbred lines without R‐genes was similar in both years. The effectiveness of quantitative resistance controlling M. incognita is confirmed in greenhouse conditions, although the durability of Me1 and Me3 when combined with quantitative resistance factors was not seen to increase.  相似文献   

Effects of protein and carbohydrate levels on survival,consumption and gonad index in adult sea urchin Strongylocentrotus purpuratus (Stimpson 1857) from Baja California,Mexico          下载免费PDF全文

Diana Maria Cuesta‐Gomez  M del Pilar Sánchez‐Saavedra 《Aquaculture Research》2017,48(4):1596-1607

A greater understanding of dietary protein and carbohydrate levels with regard to gonad production in Strongylocentrotus purpuratus would increase our nutritional knowledge of this sea urchin and guide the development of formulated diets for such aquaculture target species. A total of 255 purple sea urchins were captured from Ensenada Bay, Mexico, and maintained in 200‐L tanks for 9 weeks. Formulated diets that contained 30%, 26%, 23%, 20% and 17% of protein and 42%, 46%, 50%, 54% and 58% carbohydrates were offered ad libitum. Survival was affected by diets; urchins that were fed high‐protein–low‐carbohydrate diet experienced decreased survival. No significant differences were found in gonad index, but gonad production efficiency was lower in urchins that were fed a medium‐low‐protein–medium‐high‐carbohydrate diet. Urchins that were fed high carbohydrate levels utilized protein more efficiently and showed better digestibility of the diet and protein. These data suggest that all of our diets support gonad growth, but in terms of consumption, a diet that contains protein levels of 17% and 23% with carbohydrate levels of 50% and 58% are beneficial for S. purpuratus.  相似文献   

Reproductive cycle of the sea cucumber <Emphasis Type="Italic">Holothuria floridana</Emphasis> in the littorals of Campeche,Mexico     

Julia Ramos-Miranda  Rodolfo del Río-Rodríguez  Domingo Flores-Hernández  Ramón Isaac Rojas-González  Mónica Gómez-Solano  Ana Delia Cu-Escamilla  Francisco Gómez-Criollo  Atahualpa Sosa-López  Yassir Eden Torres-Rojas  Paloma Juárez-Camargo 《Fisheries Science》2017,83(5):699-714

The reproduction of Holothuria floridana in Campeche bay, southern Gulf of Mexico, was investigated over a period of 12 months by macroscopic and histological examination of the gonad and gametogenesis. A total of 1938 specimens were collected. Their body gutted weight and body gutted length ranged from 15 to 225 g and 5 to 21 cm, respectively. Percentage of the gonad weight to the gutted body weight (gonad index, GI) increased steadily from December to April, rapidly declined in May, and remained low during the following months. GI displayed a negative correlation with temperature of the habitat and no correlation with salinity. The gonad maturity scale with five stages was developed from macroscopic and microscopic observations; I, recovery; II, growing; III, early mature; IV, mature and V, spent. Stages III to V were observed all around the year, suggesting that this species displays continuous reproduction with two peaks of spawning events; from March to April and in September. The presence of viscera regurgitated individuals caused high variability in GI. The sex-ratio varied from 1:1 (December 2013 to June 2014), to 1.37:1 (November 2013); we suggest that this may be the consequence of unintentional selective fishing. The body length and body weight at the first maturity were calculated to be 13.4 cm and 87.0 g, respectively. For resource management it will be necessary to address some reference points like harvest season and avoidance of catches shorter than length at first maturity.  相似文献   

Influence of microbiota in the susceptibility of parasitic wasps to abamectin insecticide: deep sequencing,esterase and toxicity tests     

María del Mar Fernndez  Ivan Meeus  Annelies Billiet  Filip Van Nieuwerburgh  Dieter Deforce  Peter Vandamme  Elisa Viuela  Guy Smagghe 《Pest management science》2019,75(1):79-86

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Assessing the spawning season in common dentex (Dentex dentex) using microsatellites     

Yaisel J Borrell  Gloria Blanco  Emilia Vázquez  Jorge A Piñera  Gemma Gimenez  Alicia Estévez  & Jose A Sánchez 《Aquaculture Research》2008,39(12):1258-1267

A set of five variable microsatellite markers was used for the genetic characterization of two common dentex ( Dentex dentex ) broodstocks from an experimental hatchery and for the screening of the egg batches spawned during the complete spawn season in 2006. After parentage assignment, simulations were performed for the hatchery 1 broodstocks; the microsatellite set correctly assigned over 93% of descendants to parents when one parent was known and 80% when neither parent was known. Of the 261 eggs that the DNA was correctly amplified from, 254 were successfully assigned to a parental couple. More than one female or male took part (at the same point in time) in the spawning season. However, we observed 'dominant' individuals that produced high proportions of the descendants (unequal reproductive success) in all the sampling periods, although the contributions of these dominant individuals could change over time. This phenomenon reduces the effective breeding numbers, and could lead to inbreeding if this factor is not taken into account when the next parental generation is obtained. This factor should also be considered in aquaculture selection programmes because the dominant breeders may not be the most interesting individuals for commercial or productive schemes.  相似文献   

Kepone: hazard to aquatic organisms     

Hansen DJ  Wilson AJ  Nimmo del WR  Schimmel SC  Bahner LH  Huggett R 《Science (New York, N.Y.)》1976,193(4253):528

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实时实地氮肥管理对水稻产量和氮素利用率的影响   总被引：117，自引：12，他引：117  

刘立军  桑大志  刘翠莲  王志琴  杨建昌  朱庆森 《中国农业科学》2003,36(12):1456-1461

 以籼型三系杂交稻汕优 63为材料 ,对不同氮肥管理的农艺和经济表现进行了评价。结果表明 ,未施氮肥 (空白区 )的产量为 6.8～ 7.4t·ha- 1,表明试验田背景氮颇高。与农民习惯施肥法 (氮肥 2 40kg·ha- 1)相比 ,改良的农民施肥法 (农民习惯施氮量的 70 % )、实时氮肥管理 (依据叶绿素仪测定值进行的施肥方法 )和实地氮肥管理(施氮时期、施氮量和叶绿素仪测定值相结合的施肥方法 )分别增产 9.2 %～ 10 .3 %、3 .3 %～ 7.0 %和 8.9%～ 9.3 % ,氮肥农学利用率分别提高了 110 .5%～ 13 5.6%、2 0 4.3 %～ 2 97.0 %和 2 0 0 .9%～ 2 76.4%。以上结果表明 ,在产量不降低甚至有所增加的前提下 ,实时、实地氮肥管理可以减少氮肥施用量 ,较大幅度地提高水稻氮肥利用率。另外 ,实时、实地氮肥管理还可以降低稻米的垩白率和垩白度 ,改善稻米的外观品质  相似文献   

Isolation and inhibitory effect of anti-<Emphasis Type="Italic">Vibrio</Emphasis> substances from <Emphasis Type="Italic">Pseudoalteromonas</Emphasis> sp. A1-J11 isolated from the coastal sea water of Kagoshima Bay     

Carmelo S del Castillo  Md Iftekharul Wahid  Takeshi Yoshikawa  Taizo Sakaia 《Fisheries Science》2008,74(1):174-179

ABSTRACT:   Among several marine antagonistic bacteria isolated from the sea water of Kagoshima Bay, Pseudoalteromonas sp. A1-J11 was found to produce anti- Vibrio substances. The anti- Vibrio substances were extracted from the culture supernatant of the strain with chloroform and isolated using reverse-phase (Cosmosil 75C₁₈-OPN) column chromatography followed by high-pressure liquid chromatography (Mightysil RP-18 GP Aqua). Purified substances, designated as AVS-03 a , c and d showed similar ultraviolet absorption spectra with λ_max at 215, 235, 315 and 327 nm in methanol. AVS-03 d , the major anti- Vibrio substance, was thermostable up to 100°C and pH stable over a pH range higher than 4.0, and also showed strong inhibitory activities, specifically against Vibrio harveyi strains.  相似文献