Nuove segnalazioni di funghi entomogeni

Abstract

New records of entomogenous fungi. — New records of six entomogenous fungi, three Ascomycetes (Cordyceps lloydii Fawcett, C. memorabilis Ces., C. riverae Pacioni) and three Deuteromycetes (Akantomyces aranearum (Petch) Mains, Hirsutella citriformis Speare, Troglobiomyces guignardii (Maheu) Pacioni) are given. The new records allow to expand the known area of distribution of these parasites, to confirm the particular condition for fructification needed by some of them and to give new details for the less common species.     

Agrobacterium rhizogenes-mediated transformation and plant regeneration of four Gentiana species

Shoots of micropropagated Gentiana acaulis, G. cruciata, G. lutea, and G. purpurea were inoculated with suspensions of Agrobacterium rhizogenes cells, strains ATCC 15834 or A4M70GUS. Adventitious roots appeared at the sites of inoculation in all 4 species. Root tips were excised and cultured on growth regulator-free media for 2-6 years. They exhibited very high branching and plagiotropism. Spontaneous bud initiation occurred in roots of G. cruciata. Roots of G. lutea, G. acaulis and G. purpurea were cultured on media with high kinetin concentration, which induced the formation of friable callus tissues. Only in G. purpurea were these calluses organogenic. Regenerated shoots of G. cruciata and G. purpurea gave rise to plants, that displayed the typical phenotypes of A. rhizogenes-transformed plants: short internodes and rolled leaves. In the roots of G. acaulis and G. cruciata, transformed with A. rhizogenes A4M70GUS, a positive reaction with X-gluc indicated the activity of β-glucuronidase. The DNA extracted from hairy roots and from the roots of transgenic plants hybridized with the appropriate genomic probes in Southern blotting. This is taken as evidence of the stable genetic transformation in the 4 Gentiana species. This revised version was published online in June 2006 with corrections to the Cover Date.     

CHS基因起源初探及其在被子植物中的进化分析

利用PCR与TAIL-PCR方法,从半月苔(Lunulariacruciata(L.)Dum.exLindb.)中获得了一段长约1000bp的基因片段,它与已知的CHS基因在核苷酸水平上的相似性大于56%,在氨基酸水平上的相似性大于60%,所推断的氨基酸序列中酶反应的4个催化位点与已知晶体结构的紫花苜蓿MCHS2A上的催化位点相同,首次证明了苔类植物中可能存在类CHS基因,将CHS基因的起源时间推到苔藓类植物出现之前。以该序列和两种蕨类植物(Psilotumnudum(L.)Griseb.和EquisetumarvenseL.)的CHS序列作为外类群,应用邻接法、最大简约法和最大似然法分别构建了被子植物的CHS的分子系统树。结果表明,大部分科中的CHS分布在不同的分支上,而十字花科、豆科和禾本科各自聚成一个单系类群。以邻接树为依据,对茄科、旋花科和菊科的CHS基因进行了相对碱基替换速率的检测,发现这三个科内或科间序列的替换速率不一致。被子植物的CHS基因在基因拷贝数目、碱基替换速率以及重复/丢失事件的发生上都存在较大的差异,这种差异可能与被子植物的生活史、生活环境、花的特性以及对外界的防御系统等的多样性相关。     

Nitric oxide synthase (NOS) in the Japanese fireflies Luciola lateralis and Luciola cruciata

Species-specific flash patterns in firefly species are important for the investigation of the evolution of Lampyridae. Since nitric oxide synthase (NOS) is one of the key enzymes controlling flash patterns, we determined the cDNA sequences of NOS in the Japanese fireflies Luciola lateralis and L. cruciata. The identity of the NOS sequences was very high between these 2 species. Firefly NOS also exhibited a high identity with those of other insect species, and the cofactor-binding domains were particularly well conserved. Many negatively selected sites were detected throughout the NOS sequences; however, no positive selection was detected. The phylogenetic relationship of insect NOS was different from that of the general classification system, although the lineages corresponded to the major recognized taxonomic groups.     

Micropropagation of four Gentiana species (G. lutea, G. cruciata, G. purpurea and G. acaulis)

The growth of axillary shoots was initiated on nodal stem segments, excised from aseptically grown seedlings of Gentiana acaulis L., G. cruciata L., G. lutea L. and G. purpurea L. In later subcultures, a basal callus tissue developed on the shoots, giving rise to de novo formed buds. Optimum benzyladenine and indoleacetic acid combinations for shoot development were established. They were slightly different in the four species. From 35-70% of shoots rooted spontaneously, except in G. lutea, in which adventitious roots were induced by applying naphthaleneacetic acid. It was conduded that the four Gentiana species were amenable to propagation in vitro. This revised version was published online in June 2006 with corrections to the Cover Date.     

CHS基因起源初探及其在被子植物中的进化分析

利用PCR与TAlL-PCR方法,从半月苔(Lunularia cructata(L.)Dum.ex Lindb)中获得了一段长约l 000 bp的基因片段,它与已知的CHS基因在核苷酸水平上的相似性大于56%,在氨基酸水平上的相似性大于60%,所推断的氨基酸序列中酶反应的4个催化位点与已知晶体结构的紫花苜蓿MCHS2A上的催化位点相同,首次证明了苔类植物中可能存在类CHS基因,将CHS基因的起源时间推到苔藓类植物出现之前.以该序列和两种蕨类植物(Psilotumnudum(L.)Griseb.和Equisetum arvense L.)的CHS序列作为外类群,应用邻接法、最大简约法和最大似然法分别构建了被子植物的CHS的分子系统树.结果表明,大部分科中的CHS分布在不同的分支上,而十字花科、可科和禾本科各自聚成一个单系类群.以邻接树为依据,对茄科、旋花科和菊科的CHS基因进行了相对碱基替换速率的检测,发现这三个科内或科间序列的替换速率不一致.被子植物的CHS基因在基因拷贝数目、碱基替换速率以及重复/丢失事件的发生上都存在较大的差异,这种差异可能与被子植物的生活史、生活环境、花的特性以及对外界的防御系统等的多样性相关.     

Apparent increase in fertility of Lunularia cruciata (L.) Lind. (Marchantiophyta) in Britain associated with climate change

Until recently, fertile colonies of the unisexual Mediterranean liverwort Lunularia cruciata were considered to have a restricted distribution in Britain, due in particular to damaging effects of cold winters. Records of male-expressing plants and sporophytes were almost restricted to southern parts of England and Wales, while female-fertile plants had a somewhat wider range. A different picture has emerged from a more recent survey and, together with findings of other recorders, fertile plants of both genders of L. cruciata have been found in more northerly localities. Sporophytes have also been recorded somewhat more widely, but are likely to be limited by both separation of the sexes and a female-biased sex ratio. The British distribution of fertile plants is compared from records before and after 1990 since when there has been an increase in seasonal and annual temperature. It is suggested that warmer conditions have promoted an increase in fertility. This appears to be the first proposed example of recent climate change influencing bryophyte reproductive biology. Phenological observations in north-west Wales indicated a prolonged and broadly synchronous sequential production of archegonia and antheridia.     

Lunularia cruciata, a potential in vitro host for Glomus proliferum and G. intraradices

A study was conducted to define culture conditions for in vitro growth arbuscular mycorrhizal fungi (AMF) with liverworts as hosts. Lunularia cruciata (L.) Dumortier ex. Lindberg developed in vitro monoxenic mycothalli with both Glomus proliferum Dalpé & Declerck (MUCL 41827) and Glomus intraradices Schenck & Smith (MUCL 43204). AMF inoculated plants were co-cultured in plastic Petri dishes with semi-solidified medium supplemented with sucrose and grown under filtered light. Mycothalli of L. cruciata produced external hyphae and spores in quantities equivalent to those obtained with Ri T-DNA transformed root systems.     

Effect of rainfall on the long-term population dynamics of the aquatic firefly Luciola cruciata

Long‐term observations of adult populations of the aquatic Genji firefly, Luciola cruciata (Coleoptera: Lampyridae), were conducted using a simple flash counting method from 1975 to 2006 at four locations in Kyoto City, Japan. The relative population sizes of adult L. cruciata at these sites fluctuated almost synchronously, indicating the influence of large‐scale environmental phenomena such as weather conditions on population dynamics. Rainfall in September and the latter half of July caused a significant decrease in the population size. The frequent rainfall during these months may have caused considerable drift in the emergence of early instars of firefly larvae and a decrease in their foraging activity.