我国森林采伐更新的发展与展望

本文根据国内外森林采伐更新的现状，各种采伐方式的利弊，试图探索一条适合我国国情的森林采伐更新方式和合理开发我国森林资源的新途径。     

卡麦若莎草莓离体再生体系的研究

卡麦若(Camarosa)为草莓新品种,果大,抗痛性强,在我国广泛种植.试验对卡麦若莎(Camarosa)进行组织培养,选择最佳外植体,最佳消毒时间,最佳诱导培养基,最佳分化培养基与生根培养.结果表明:最佳外植体是叶片,0.1%升汞对外植体消毒2 min时效果最好;诱导愈伤的最佳培养基为:MS 1.5 mg·L-16-BA 0.1 mg·L-1NAA;最佳分化培养基:MS 2.0mg·L-16-BA 0.2 mg·L-1NAA;最佳生根培养基:1/2MS 0.25 mg·L-16-BA,此品种容易形成高效再生体系.     

樱桃砧木CAB-6p离体叶片再生体系的优化

以欧洲甜樱桃优良矮化砧木CAB-6p试管苗幼嫩叶片为试材,从基本培养基、激素配比、叶片生理状态和培养基中琼脂用量等方面对影响离体叶片再生的关键因素进行了研究。结果表明,CAB-6p试管苗幼嫩叶片以WPM为基本培养基再生效果最好,明显优于QL和DKW培养基,1/2MS培养基再生效果最差;最佳激素配比是BA2mg/L+IAA2mg/L,用IBA或NAA替代IAA出现愈伤组织生长量大但再生率低;CAB-6p试管苗顶部新发出合拢的幼嫩叶片再生能力最高,半展开的幼嫩叶片和完全展开的幼嫩叶片未能再生植株;用4.5g/L琼脂配制偏软的再生培养基明显有利于提高离体叶片的再生效率。通过以上几个方面的优化,建立CAB-6p试管苗幼嫩叶片高效离体再生技术体系,再生率可稳定地保持在90%左右,平均每叶再生4～5芽。     

Effects of harvesting on soil properties and regeneration quality in larch-birch forest in China

INTRoDUCTIONoneopeationsite,locatCdin5O'47'Nandl24"2o'E,wasselectCdastCstsite,Wherethelarch(Larixgmelinii)dominatesmostlythetreepopulahonwithnearlyeightypercentin.standingvolume.Theresttreesarebirch.Annalprecipitation,tethperAnandvaPori-zationare5lonun,-2.4Cand3lommrespec-tively.Elevationisaround45Omoversealevel.CuttingmethodsusedinthissitewereselechvecuningandclearcuttingwithgrQUndtractorskiddingaswellasasmallpwtofani-malskidding.CHANGESoFSoILPRoPERTIESCAUSEDBYHARVESTI…     

Advance in islet β cell development and regeneration

Islet β cells excrete insulin and play a crucial role in glucose homeostasis. Decreased β cell mass or/and β cell dysfunction are one of the fundamental characteristics of diabetes. The advance in understanding β cell development and regeneration provides new approaches to diabetes treatment. This review focuses on the molecular mechanism about β cell development and the sources for β cell regeneration.     

高粱组织培养的研究进展

本文回顾了高粱组织培养的方法、影响因素和研究进展,并对这些再生技术体系的优缺点进行了简单比较,对高粱组织培养中存在的褐化以及愈伤组织胚性保持等问题作出了初步分析。     

裂叶秋海棠组织培养及植株再生研究

以裂叶秋海棠（Begonia palmata D.Don）种子获得无菌苗,取其叶片为外植体,对裂叶秋海棠叶片丛生芽诱导和植株再生进行了研究。结果表明：MS＋TDZ 0.5 mg/L诱导叶片外植体产生不定芽的诱导效果最佳,诱导率为100%,不定芽个数可达200个/cm2;最佳生根培养基为1/3MS＋IBA 0.2 mg/L,2周后生根率达到100%。     

Trends in North American and European regeneration research under the ecosystem management paradigm

Forest management on many ownerships in North America and Europe has shifted toward the ecosystem management paradigm. The associated shift toward multiple management objectives and focus on natural development patterns should also be reflected in regeneration research efforts. As new information needs arise, research questions and approaches should be evaluated whether they are still appropriate. Specifically, spatial and temporal scales of research studies need to be expanded to accommodate complex sets of management objectives and constraints, rather than being focused on optimal tree regeneration. At the same time, silviculturists are asked to utilize natural trends as a guide for management, but most natural disturbance studies have focused on stand structures and not the regeneration processes. Criteria commonly used to describe disturbance regimes need to be modified to better guide regeneration research efforts under the ecosystem management paradigm.     

The role of different sources of tree regeneration in the initial stages of natural forest recovery after logging of conifer plantation in a warm-temperate region

We analyzed the role of regeneration type (surviving from advanced regeneration, resprouting from advanced regeneration, or newly recruited seedlings) in determining the quantity and quality of individuals in reestablishing a natural forest following clear-cutting of a conifer plantation. We experimentally clear-cut a plantation and undertook a detailed tree census before and after clear-cutting. After clear-cutting, a species composition partially representing warm-temperate evergreen broadleaf forest was present in the form of surviving and resprouted individuals originating from advanced regeneration that had established in the Chamaecyparis obtusa plantation. On the other hand, seedlings that established after clear-cutting were dominated by pioneer species, and the number of seedlings was far greater than the number of individuals originating from advanced regeneration. Our results suggest that the role of regeneration type would differ in relation to the objectives for forest recovery. When any kind of woody cover of the ground surface after clear-cutting would suffice, we suggest that the contribution of pioneer seedlings originating from buried seeds would be important. If the recovery objective is to form a simple evergreen broadleaf forest, such as a coppice woodland, all three sources of regeneration would play a similar role, provided the understory before clear-cutting was as well developed as the one in this study. If rapid establishment of a lucidophyllous forest with diverse species composition is desired, the role of the surviving and resprouting individuals originating from the advanced regeneration would be much more important.