Differential Response of Liverwort (Marchantia polymorpha) Tissue to POST-Applied Quinoclamine

Abstract

Quinoclamine is used in Europe, and was under evaluation in the Unites States for the control of liverwort in nursery crops. Liverwort is a nonvascular, chlorophyll-containing plant that can be problematic in greenhouse and nursery crops. POST-applied quinoclamine controls liverwort. However, liverwort structures vary in their sensitivity to POST-applied quinoclamine. Specifically, archegonial receptacles (female) are much more tolerant of quinoclamine than either antheridial receptacles (male) or thalli (leaflike structures). A series of studies were conducted to, first, document the degree of differential sensitivity between tissues to quinoclamine, and second, to determine the basis of this differential sensitivity. The dose that results in 50% of the population being controlled (I50) of antheridial receptacles and juvenile thalli were estimated to be 1.60 and 1.27 kg·ha−1, respectively. TheI50of archegonial receptacles could not be estimated, but exceeded 10.45 kg·ha−1. Chlorophyll content varied between liverwort tissues, but the content did not correlate to quinoclamine sensitivity. Absorption of14C after application of radiolabeled quinoclamine was less in archegonial receptacles than in either antheridial receptacles or thalli. Scanning electron microscopy of the surface of the liverwort tissues revealed that archegonial receptacles had smaller pores (equivalent to stomata in higher plants) than either antheridial receptacles or thalli. The tolerance of archegonial receptacles to quinoclamine can be partially, but not exclusively, attributed to reduced absorption. This reduced absorption may be attributed to the limited pore size and less total pore area of the archegonial receptacles.

Establishment of a New Model Sea Anemone for Comparative Studies on Cnidarian-Algal Symbiosis

“…Even if chlorophyll synthesis can be inhibited by Kiredar treatment in some cases, it is likely that such inhibition was not a major cause of ejecting algal cells, considering the lack of obvious reduction in algal cells ejected by A. atodai (see ). Based on the structural features of quinones, it is presumed that quinoclamine removes electrons from the photosystem (Altland et al, 2011), like the herbicide paraquat (Qian et al, 2009), and results in the generation of reactive oxygen species (ROS), which is suggested to be a major cause of bleaching in corals (Lesser, 2011). This also seems to be the case in sea anemone bleaching, considering our findings that bleaching occurred under light, but not dark, conditions.…”

Métodos de controle químicos e físicos de Marchantia polymorpha

“…Estes dois tratamentos foram deixados a pleno sol, durante 45 dias, conforme descrito por LOPES et al (2000) e GHINI et al (1994).…”

“…Na região, a espé-cie tem acarretado consideráveis reduções no desenvolvimento, qualidade e valorização das mudas, devido à total ocupação da superfície do recipiente utilizado na produção. No processo competitivo, as sementes de espécies nativas não conseguem emergir, já que se forma uma barreira física, impedindo também a infiltração da água, prejudicando o desenvolvimento radicular das mudas (ALTLAND et al, 2011). Nos Estados Unidos, os mesmos prejuízos também foram encontrados pelos produtores (NEWBY, 2006).…”

Practice in Nursery Weed Control—Review and Meta-Analysis

“…Some of those chemicals, such as iodomethane reached a 100% weed control efficacy (Fennimore et al, 2008). Later, herbicides, such as oryzalin, glyphosate, flumioxazin, oxyfluorfen, pendimethalin, isoxaben, trifluralin, and their combinations become more widely tested, other herbicides that have both preemergence and postemergence effects, such as quinoclamine was also tested in different studies (Porter, 1996;Willoughby et al, 2003;Altland et al, 2004Altland et al, , 2007Altland et al, , 2008Altland et al, , 2011Awan et al, 2006;Judge and Neal, 2006;Qasem, 2006Qasem, , 2007Richardson and Zandstra, 2009;Wehtje et al, 2010aWehtje et al, ,b, 2012Rahman et al, 2011;Abit and Hanson, 2013;Ramalingam et al, 2013;Vasic et al, 2015;Marble et al, 2016b). Most of the herbicides, such as oxadiazon, flumioxazin, and prodiamine, presented satisfactory weed control performances (Judge and Neal, 2006;Amoroso et al, 2009;Wehtje et al, 2010a).…”