Effects of post-fire management practices and slope-aspect on medium-term Spanish black pine regeneration: implications of using a direct seeding strategy in burnt areas

The natural regeneration of non-serotinous Spanish black pine (Pinus nigra Arn. ssp. salzmannii) is known to be null or limited after severe wildfires. However, it remains challenging to define efficient management strategies within the burnt area, which can help to increase the post-fire resilience of this species. We conducted a direct seeding experiment during 2011–2015 to assess the effect of different post-fire management treatments (control, soil ripping, woodchips, and soil ripping?+?woodchips) performed in opposite slope-aspects (north- and south-facing) on pine emergence, seed predation, survival, growth, and biomass allocation during the early stages of seedling development (1–5 years) after a severe wildfire. Our results showed that the slope-aspect did not have an important effect in both the seedling emergence and seed predation rates. In contrast, the influence of slope-aspect was significant as both survival and growth of pine seedlings were reduced at the south-facing slope-aspect compared to the north-facing slope-aspect due to harsher environmental conditions. A variable and reduced impact on seedling emergence and seed predation rates was induced by both soil ripping and woodchips treatments. Overall, post-fire management treatments helped to enhance survival rates during early growth stages, although this effect was short-lasting. This knowledge can be used to define post-fire seeding management strategies oriented to enhance the resilience of severely burnt pine forest stands; therefore, while both the soil ripping and woodchips treatments might not be practices leading to increase their post-fire regeneration, direct seeding at north-facing slope-aspects could be a more appropriate management strategy.     

Norway spruce emblings as cutting donors for tree breeding and production

In the Nordic countries, Norway spruce (Picea abies) is a major species in tree breeding. In order to facilitate breeding work and availability of highly bred forest regeneration material, the time required for breeding and implementation of results should be shortened. This could be done by accelerating production of clonal material for field testing, and possibly for planting stock, by combining production of rooted cuttings with somatic embryogenesis (SE). This would allow efficient production of numerous plants of the same genotype, with equal age and propagation history between genotypes. In the present work, we studied the rooting potential of cuttings from Norway spruce emblings. Altogether 36 clones from 12 families representing elite breeding materials and ornamental forms were examined under different rooting conditions (container type and rooting media) in 2015 and 2016. Our results show that Norway spruce emblings are good donors for cuttings. Best combination (peat–vermiculite mixture and Plantek 81f containers) resulted in 91% rooting, variation among the tested clones of elite breeding materials being 55–100% per treatment. The rooting variation between families is acceptable for breeding purposes. High rooting (87–96%) of ornamental forms indicates propagation potential with the combination of SE and rooted cuttings.     

Occurrence of the moth Cydia pactolana is associated with the spruce canker fungus Neonectria fuckeliana

Several young damaged Norway spruce stands in eastern and central Finland were observed from 2013 to 2016. The damage included trees with heavy resin flow, necrotic foliage, stem and branch cankers and dead trees. Pest identification resulted in the tortricid moth Cydia pactolana whose occurrence was always associated with the presence of the ascomycete pathogen Neonectria fuckeliana. Both the insect and the disease contributed to the extent of the damage, but it is not possible to say in which order they had attacked the trees. Apparently, changed climate has affected the increased occurrence of both the fungus and the moth. However, the characteristics of the insect–fungus interaction and the factors contributing to the coincidences are unknown. Emerging coexistence or potential symbiosis of the two damaging agents is a serious threat for Norway spruce cultivation. Understanding the biology of this fungus–insect interaction is important for controlling them.     

家犬基因组及表型特征的遗传研究进展

犬具有丰富的遗传多样性,犬、人和鼠3种生物的基因组分析发现,犬与人、鼠的保守性非常高。犬的特殊群体结构使其成为研究形态、行为等多样性、哺乳动物进化遗传基础和疾病的良好模型。本文就家犬起源进化、基因组结构、犬表型特征的遗传变异、基因定位等研究进展做一综述,以期为犬遗传育种研究提供理论基础,并为人类疾病的预防、诊断和治疗提供新的思路与方法。     

大兴安岭采伐迹地主要目的树种的天然更新

对不同采伐方式(经营择伐、二次渐伐和皆伐)、林分组成、坡向、坡位、郁闭度、土壤厚度、下木盖度、地被物盖度等条件下样地中主要目的树种的更新情况进行了调查。结果表明:经营择伐林分有效天然更新株数最多,温度和光照条件是决定兴安落叶松更新的重要条件;经营择伐林分兴安落叶松天然更新株数主要受林分郁闭度的制约,皆伐和二次渐伐林分兴安落叶松天然更新株数主要受地表草本植物的制约;二次渐伐林分不同坡位间不但更新数量存在差异,而且树木的生长状况差异也很大。     

采摘果园经营管理策略研究——以尤溪县洋中镇老友生态农场为例

果园采摘是休闲农业的一个重要类型，在减少农产品流通环节、开拓农产品销售渠道、创建品牌、发展三产融合、提升农业经济效益方面具有明显的优势。笔者以尤溪县洋中镇老友生态农场为例，分析了采摘园存在缺乏规划、服务理念不到位、采摘品种单一、同质化竞争激烈、劳动力成本高、精细化管理不足、品牌建设滞后、营销推广不足等问题。提出对采摘园进行准确定位、采用高标准的绿色种植技术、配套完善服务设施、实现功能分区、利用新媒体进行营销推广、树立品牌等经营管理措施，以带动传统果园转型升级，实现乡村产业振兴。     

基于全基因组重测序分析藏猪骨骼肌发育相关基因

为从全基因组水平探索影响藏猪骨骼肌发育的遗传变异，本研究对5头迪庆藏猪进行全基因组重测序，并合并NCBI数据库中来自3个省的藏猪、与藏猪同样小体型及生长慢的巴马香猪、及体型大且生长快速的杜洛克和大白猪共70个猪只的全基因组重测序数据进行整合分析，获得全基因组SNP后结合选择信号检测与等位基因频率(AF)分析鉴定藏猪-香猪与杜洛克-大白猪的遗传差异；利用GO和KEGG功能富集分析藏猪骨骼肌转录组与蛋白组相关基因。结果发现:1)2 211个基因在藏猪-香猪与杜洛克-大白猪2个比较组中存在遗传差异，138个基因富集到骨骼肌发育相关的GO功能集及KEGG通路；2)9个基因(UCHL3、POSTN、COL12A1、PGK1、JPH1、GPT2、RBFOX1、FLNB和DCX)已报道参与藏猪60 d胚胎背最长肌发育调控，1个(CKM)参与6月龄藏猪背最长肌发育调控；3)10个基因共包含936个SNP，其中655个SNP位于基因间区，255个是内含子变异，少量SNP是外显子及调控区变异。本研究从全基因组水平鉴定了与藏猪骨骼肌发育相关基因及其遗传变异，为以后持续深入解析藏猪骨骼肌发育的遗传机制提供参考。