The Experts below are selected from a list of 1887 Experts worldwide ranked by ideXlab platform

Andrew A. Meharg - One of the best experts on this subject based on the ideXlab platform.

  • Arbuscular mycorrhizal fungi confer enhanced arsenate resistance on Holcus lanatus
    New Phytologist, 2002
    Co-Authors: C. Gonzalez‐chavez, Peter J. F. Harris, John C. Dodd, Andrew A. Meharg
    Abstract:

    Summary • The role of arbuscular mycorrhizal fungi (AMF) in arsenate resistance in arbuscular mycorrhizal associations is investigated here for two Glomus spp. isolated from the arsenate-resistant grass Holcus lanatus. • Glomus mosseae and Glomus caledonium were isolated from H. lanatus growing on an arsenic-contaminated mine-spoil soil. The arsenate resistance of spores was compared with nonmine isolates using a germination assay. Short-term arsenate influx into roots and long-term plant accumulation of arsenic by plants were also investigated in uninfected arsenate resistant and nonresistant plants and in plants infected with mine and nonmine AMF. • Mine AMF isolates were arsenate resistant compared with nonmine isolates. Resistant and nonresistant G. mosseae both suppressed high-affinity arsenate/phosphate transport into the roots of both resistant and nonresistant H. lanatus. Resistant AMF colonization of resistant H. lanatus growing in contaminated mine spoil reduced arsenate uptake by the host. • We conclude that AMF have evolved arsenate resistance, and conferred enhanced resistance on H. lanatus.

  • Phytochelatins are involved in differential arsenate tolerance in Holcus lanatus.
    Plant physiology, 2001
    Co-Authors: Jeanette Hartley-whitaker, Gillian Ainsworth, Riet Vooijs, Wilma Ten Bookum, Henk Schat, Andrew A. Meharg
    Abstract:

    Arsenate tolerance is conferred by suppression of the high-affinity phosphate/arsenate uptake system, which greatly reduces arsenate influx in a number of higher plant species. Despite this suppressed uptake, arsenate-tolerant plants can still accumulate high levels of As over their lifetime, suggesting that constitutive detoxification mechanisms may be required. Phytochelatins are thiol-rich peptides, whose production is induced by a range of metals and metalloids including arsenate. This study provides evidence for the role of phytochelatins in the detoxification of arsenate in arsenate-tolerant Holcus lanatus. Elevated levels of phytochelatin were measured in plants with a range of tolerance to arsenate at equivalent levels of arsenate stress, measured as inhibition of root growth. The results suggest that arsenate tolerance in H. lanatus requires both adaptive suppression of the high-affinity phosphate uptake system and constitutive phytochelatin production.

  • Genetic correlation between arsenate tolerance and the rate of influx of arsenate and phosphate in Holcus lanatus L.
    Heredity, 1992
    Co-Authors: Andrew A. Meharg, Mark R. Macnair
    Abstract:

    Genetic correlation between arsenate tolerance and the rate of influx of arsenate and phosphate in Holcus lanatus L.

  • The genetics of arsenate tolerance in Yorkshire fog, Holcus lanatus L.
    Heredity, 1992
    Co-Authors: Mark R. Macnair, Quinton J. Cumbes, Andrew A. Meharg
    Abstract:

    The genetics of arsenate tolerance in Holcus lanatus is investigated. Three tolerant plants from an abandoned arsenic mine, and three non-tolerant plants and one less tolerant plant (C9) from an uncontaminated site were crossed. Five polycrosses between plants from F1 crosses between mine and non-tolerants were set up. Four polycrosses between tolerant F2 progeny, and four polycrosses between non-tolerant F2 progeny, were established. A polycross involving the progeny of a single tolerant plant allowed to cross at random with a normal population was also established. The results are broadly compatible with a single-gene model for tolerance, with tolerance being dominant. The majority of F2 crosses segregated in to 3:1 ratios, and backcrosses gave 1:1 ratios. The crosses between C9 and non-tolerants gave 1:1 ratios, which suggests that the less tolerant C9 was heterozygous for tolerance. All crosses between non-tolerants gave all non-tolerant offspring. In one cross a major gene for albinism also segregated, and linkage of the tolerance gene to this gene (r.f. = 35%) was demonstrated. A number of families produced progeny ratios incompatible with the simple major gene model. Possible causes of these anomalous crosses are discussed and it is suggested that the tolerance gene may show variable penetrance depending on the genetic background.

Zhiyuan Yao - One of the best experts on this subject based on the ideXlab platform.

  • two new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from pakistan
    Zootaxa, 2020
    Co-Authors: Tianqi Lan, Zhiyuan Yao, Abid Ali, Guo Zheng
    Abstract:

    The genus PHolcus Walckenaer, 1805 is reported from Pakistan for the first time. Two new species of the PHolcus nenjukovi species-group are described: PHolcus hamuchal Yao & Li sp. nov. (Gilgit Baltistan, male and female) and PHolcus kalam Yao & Li sp. nov. (Khyber Pakhtunkhwa, male and female). Type material is deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China.

  • ten new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from southeast asia
    Zootaxa, 2017
    Co-Authors: Tingting Dong, Guo Zheng, Zhiyuan Yao
    Abstract:

    Ten new species from six species groups of the genus PHolcus Walckenaer, 1805 are described from Southeast Asia: PHolcus bulacanensis Yao & Li sp. nov. (male & female, Philippines) from the P. bicornutus species group; P. duan Yao & Li sp. nov. (male & female, Thailand), P. ping Yao & Li sp. nov. (male & female, Vietnam) and P. vietnamensis Yao & Li sp. nov. (male & female, Vietnam) from the P. bidentatus species group; P. fuza Yao & Li sp. nov. (male & female, Thailand) and P. mueangensis Yao & Li sp. nov. (male & female, Thailand) from the P. buatong species group; P. cheni Yao & Li sp. nov. (male & female, Thailand) and P. subwan Yao & Li sp. nov. (male & female, Thailand) from the P. halabala species group; P. shuye Yao & Li sp. nov. (male & female, Indonesia) from the P. krabi species group; P. dongxue Yao & Li sp. nov. (male & female, Thailand) from the P. yichengicus species group.

  • two new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from tajikistan with the first description of female pHolcus sidorenkoi dunin 1994
    European journal of taxonomy, 2017
    Co-Authors: Tingting Dong, Guo Zheng, Abdulaziz M Davlatov, Zhiyuan Yao
    Abstract:

    Two new species of the genus PHolcus Walckenaer, 1805 are described from Tajikistan: PHolcus saidovi Yao & Li sp. nov. (♂♀) and P. shuguanensis Yao & Li sp. nov. (♂). The female of P. sidorenkoi Dunin, 1994 is reported for the first time. All belong to the P. nenjukovi species group.

  • thirteen new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from china
    Zootaxa, 2016
    Co-Authors: Tingting Dong, Guo Zheng, Zhiyuan Yao
    Abstract:

    Thirteen new species from four species groups of the genus PHolcus Walckenaer, 1805 are described from China: PHolcus yanjinensis sp. nov. (male & female, Yunnan) from the P. bidentatus species group; P. jingyangensis sp. nov. (male & female, Shaanxi), P. langensis sp. nov. (male & female, Henan) and P. longus sp. nov. (male & female, Beijing) from the P. crypticolens species group; P. huoxiaerensis sp. nov. (male, Xinjiang) from the P. ponticus species group; P. difengensis sp. nov. (male, Chongqing), P. gonggarensis sp. nov. (male & female, Tibet), P. hamaensis sp. nov. (male & female, Guizhou), P. lingguanensis sp. nov. (male & female, Henan), P. qingyunensis sp. nov. (male & female, Jiangxi), P. tangyuensis sp. nov. (male & female, Shaanxi), P. tianmuensis sp. nov. (male & female, Zhejiang) and P. zhongdongensis sp. nov. (male & female, Guangxi) from the P. yichengicus species group.

  • fifteen new species of the spider genus pHolcus araneae pholcidae from southeast asia
    Zootaxa, 2016
    Co-Authors: Tingting Dong, Guo Zheng, Zhiyuan Yao
    Abstract:

    Fifteen new species from six species groups of the genus PHolcus Walckenaer, 1805 are described from Southeast Asia: PHolcus hinsonensis sp. nov. (male & female, Thailand) and P. tharnlodensis sp. nov. (male & female, Thailand) from the P. bidentatus species group; P. kottawagamaensis sp. nov. (male & female, Sri Lanka) from the P. ethagala species group; P. cenranaensis sp. nov. (male & female, Indonesia) and P. krachensis sp. nov. (male, Thailand) from the P. gracillimus species group; P. anaiensis sp. nov. (male, Indonesia), P. ballarini sp. nov. (male & female, Thailand), P. gou sp. nov. (male & female, Myanmar), P. wan sp. nov. (male & female, Thailand) and P. zhuchuandiani sp. nov. (male & female, Indonesia) from the P. halabala species group; P. chiangmaiensis sp. nov. (male & female, Thailand) and P. taptaoensis sp. nov. (male & female, Thailand) from the P. quinquenotatus species group; P. kaebyaiensis sp. nov. (male & female, Thailand), P. musensis sp. nov. (male & female, Thailand) and P. songkhonensis sp. nov. (male & female, Thailand) from the P. yichengicus species group.

Carles Ribera - One of the best experts on this subject based on the ideXlab platform.

  • colonization and diversification of the spider genus pHolcus walckenaer 1805 araneae pholcidae in the macaronesian archipelagos evidence for long term occupancy yet rapid recent speciation
    Molecular Phylogenetics and Evolution, 2008
    Co-Authors: Dimitar Dimitrov, Miquel A Arnedo, Carles Ribera
    Abstract:

    Macaronesian archipelagos stand apart from other oceanic islands reputed as laboratories for the study of evolution by their proximity to the mainland, lack of subsidence, and steep ecological gradients. The genus PHolcus Walckenaer, 1805, commonly known as daddy-long-leg spiders, is one of the most speciose arthropod groups in the region, with 25 endemic species. In the present study, we use information from four mitochondrial genes, along with morphological data, to examine the phylogenetic relationships and diversification patterns of the genus in the region. Phylogenetic analyses support monophyly of Macaronesian PHolcus including the Moroccan species PHolcus vachoni and hence a single colonization event in the archipelagos. Madeira colonizers most likely originated from the Canaries, and a back-colonization of the nearby mainland receives further support. Estimated lineage divergence times suggest a long-time presence of PHolcus in the region, but also reveal that most present-day species are the result of recent, and probably rapid, speciation events. Diagnostic characters among Macaronesian PHolcus are confined to structures involved in copulation. Coupled with the extremely high diversification rate, the highest recorded for spiders, these copulatory characters suggest that sexual selection has played a key role in the local diversification of PHolcus in Macaronesia.

Guo Zheng - One of the best experts on this subject based on the ideXlab platform.

  • two new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from pakistan
    Zootaxa, 2020
    Co-Authors: Tianqi Lan, Zhiyuan Yao, Abid Ali, Guo Zheng
    Abstract:

    The genus PHolcus Walckenaer, 1805 is reported from Pakistan for the first time. Two new species of the PHolcus nenjukovi species-group are described: PHolcus hamuchal Yao & Li sp. nov. (Gilgit Baltistan, male and female) and PHolcus kalam Yao & Li sp. nov. (Khyber Pakhtunkhwa, male and female). Type material is deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China.

  • ten new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from southeast asia
    Zootaxa, 2017
    Co-Authors: Tingting Dong, Guo Zheng, Zhiyuan Yao
    Abstract:

    Ten new species from six species groups of the genus PHolcus Walckenaer, 1805 are described from Southeast Asia: PHolcus bulacanensis Yao & Li sp. nov. (male & female, Philippines) from the P. bicornutus species group; P. duan Yao & Li sp. nov. (male & female, Thailand), P. ping Yao & Li sp. nov. (male & female, Vietnam) and P. vietnamensis Yao & Li sp. nov. (male & female, Vietnam) from the P. bidentatus species group; P. fuza Yao & Li sp. nov. (male & female, Thailand) and P. mueangensis Yao & Li sp. nov. (male & female, Thailand) from the P. buatong species group; P. cheni Yao & Li sp. nov. (male & female, Thailand) and P. subwan Yao & Li sp. nov. (male & female, Thailand) from the P. halabala species group; P. shuye Yao & Li sp. nov. (male & female, Indonesia) from the P. krabi species group; P. dongxue Yao & Li sp. nov. (male & female, Thailand) from the P. yichengicus species group.

  • two new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from tajikistan with the first description of female pHolcus sidorenkoi dunin 1994
    European journal of taxonomy, 2017
    Co-Authors: Tingting Dong, Guo Zheng, Abdulaziz M Davlatov, Zhiyuan Yao
    Abstract:

    Two new species of the genus PHolcus Walckenaer, 1805 are described from Tajikistan: PHolcus saidovi Yao & Li sp. nov. (♂♀) and P. shuguanensis Yao & Li sp. nov. (♂). The female of P. sidorenkoi Dunin, 1994 is reported for the first time. All belong to the P. nenjukovi species group.

  • thirteen new species of the spider genus pHolcus walckenaer 1805 araneae pholcidae from china
    Zootaxa, 2016
    Co-Authors: Tingting Dong, Guo Zheng, Zhiyuan Yao
    Abstract:

    Thirteen new species from four species groups of the genus PHolcus Walckenaer, 1805 are described from China: PHolcus yanjinensis sp. nov. (male & female, Yunnan) from the P. bidentatus species group; P. jingyangensis sp. nov. (male & female, Shaanxi), P. langensis sp. nov. (male & female, Henan) and P. longus sp. nov. (male & female, Beijing) from the P. crypticolens species group; P. huoxiaerensis sp. nov. (male, Xinjiang) from the P. ponticus species group; P. difengensis sp. nov. (male, Chongqing), P. gonggarensis sp. nov. (male & female, Tibet), P. hamaensis sp. nov. (male & female, Guizhou), P. lingguanensis sp. nov. (male & female, Henan), P. qingyunensis sp. nov. (male & female, Jiangxi), P. tangyuensis sp. nov. (male & female, Shaanxi), P. tianmuensis sp. nov. (male & female, Zhejiang) and P. zhongdongensis sp. nov. (male & female, Guangxi) from the P. yichengicus species group.

  • fifteen new species of the spider genus pHolcus araneae pholcidae from southeast asia
    Zootaxa, 2016
    Co-Authors: Tingting Dong, Guo Zheng, Zhiyuan Yao
    Abstract:

    Fifteen new species from six species groups of the genus PHolcus Walckenaer, 1805 are described from Southeast Asia: PHolcus hinsonensis sp. nov. (male & female, Thailand) and P. tharnlodensis sp. nov. (male & female, Thailand) from the P. bidentatus species group; P. kottawagamaensis sp. nov. (male & female, Sri Lanka) from the P. ethagala species group; P. cenranaensis sp. nov. (male & female, Indonesia) and P. krachensis sp. nov. (male, Thailand) from the P. gracillimus species group; P. anaiensis sp. nov. (male, Indonesia), P. ballarini sp. nov. (male & female, Thailand), P. gou sp. nov. (male & female, Myanmar), P. wan sp. nov. (male & female, Thailand) and P. zhuchuandiani sp. nov. (male & female, Indonesia) from the P. halabala species group; P. chiangmaiensis sp. nov. (male & female, Thailand) and P. taptaoensis sp. nov. (male & female, Thailand) from the P. quinquenotatus species group; P. kaebyaiensis sp. nov. (male & female, Thailand), P. musensis sp. nov. (male & female, Thailand) and P. songkhonensis sp. nov. (male & female, Thailand) from the P. yichengicus species group.

López Espinosa, José Antonio - One of the best experts on this subject based on the ideXlab platform.

  • Nuevos taxones para la flora de Murcia
    2017
    Co-Authors: Solano, Pedro J., Aznar Laura, Martinez Pedro, Carrión Vilches, Miguel Angel, López Espinosa, José Antonio
    Abstract:

    This paper compiles 14 new records for Murcia province: Delphinium halteratum subsp. verdunense, Holcus mollis, Iberis amara, Kleinia neriifolia, Lavatera mauritanica, Lepidium ruderale, Moricandia moricandioides subsp. baetica, Oxalis tetraphylla, Orobanche santolinae, Pimpinella anisum, Senna alexandrina, Sisymbrium macroloma, Tordylium maximum.Se recopilan 14 nuevas citas para la flora vascular de la provincia de Murcia como Delphinium halteratum subsp. verdunense, Holcus mollis, Iberis amara, Kleinia neriifolia, Lavatera mauritanica, Lepidium ruderale, Moricandia moricandioides subsp. baetica, Oxalis tetraphylla, Orobanche santolinae, Pimpinella anisum, Senna alexandrina, Sisymbrium macroloma, Tordylium maximum

  • Nuevos taxones para la flora de Murcia
    2017
    Co-Authors: Solano, Pedro J., Martinez Pedro, Carrión Vilches, Miguel Angel, Aznar Morell Laura, López Espinosa, José Antonio
    Abstract:

    This paper compiles 14 new records for Murcia province: Delphinium halteratum subsp. verdunense, Holcus mollis, Iberis amara, Kleinia neriifolia, Lavatera mauritanica, Lepidium ruderale, Moricandia moricandioides subsp. baetica, Oxalis tetraphylla, Orobanche santolinae, Pimpinella anisum, Senna alexandrina, Sisymbrium macroloma, Tordylium maximum