马尾松二代遗传改良和良种繁育技术研究及应用

针对我国主要速生丰产用材造林树种马尾松遗传改良程度低，良种产量严重不足，人工林生产力低下等重大技术问题，在“十五”和“十一五”国家科技支撑马尾松育种专题、国家自然科学基金、86 3项目、948项目等多个课题的资助下，开展了持续10余年的马尾松二代遗传改良和良种繁育技术研究，选育出速生优质用材优良品系182个，营建二代种子园2290亩，在核心期刊上发表论文50篇（SCI收录4篇，一级期刊21篇），出版专著3部，研究成果达到国际同类研究先进水平。1.利用已近或已达轮伐期的各类遗传测定林，系统揭示了马尾松主要生长和材性等经济性状的一般配合力( GCA)／特殊配合力(SCA)、加性／显性／上位基因效应、父本／母本效应、杂种优势、近交衰退等遗传规律，选育出速生优质新品系（种源、家系、无性系和杂交组合）182个，材积增益20%以上，木材密度提高4%。其中审定优良家系37个、优良无性系4个、优良个体47个，认定马尾松二代种子园良种1个。2.选出速生优质马尾松二代育种亲本320个，在主要育种区构建了二代育种群体4个。揭示了二代育种亲本的遗传变异规律和遗传多样性，建立了杂交亲本的分子标记辅助选配和杂种优势顸测技术，创制了三代育种新种质340份，全面推进了马尾松高世代育种。3.选用材积增益达30%-60%的二代亲本作为建园材料，解决了采用圃地大规格容器嫁接苗一次定植成园的马尾松二代无性系种子园营建技术，及截干矮化和整形修剪的“果园式”早实丰产技术，新建了二代无性系矮化种子园2290亩，全面推进了马尾松用种升级和二代良种造林。4.阐明了马尾松有效利用土壤磷素和高效觅取异质土壤养分的行为与机制，构建了马尾松磷效率的特异性指标体系，研制出高磷效率基因型早期鉴定和综合选择技术，选育出高磷效率优良基因型21个，增强了二代良种在低磷贫瘠立地上的营养效率和高产特性。5.确定了马尾松良种（优良种源）的合理布局，提出了良种（优良种源）与立地、施用磷肥、初植密度等主要育林措施的优化配置及提高觅养能力的营林技术。

Against the backdrop of major technical challenges including low genetic improvement level, severely insufficient improved seed yield, and low productivity of planted forests for Pinus massoniana—a dominant fast-growing and high-yield timber plantation tree species in China—over a decade of sustained research on second-generation genetic improvement and improved seed propagation technology of Pinus massoniana was conducted with funding from multiple projects, such as the Pinus massoniana breeding topics under the National Key Technology R&D Program during the Tenth Five-Year Plan and Eleventh Five-Year Plan periods, the National Natural Science Foundation of China, the 863 Program, and the 948 Project. A total of 182 elite fast-growing and high-quality timber lines were selected, 2290 mu of second-generation seed orchards were established, 50 papers were published in core academic journals (including 4 SCI-indexed papers and 21 papers in first-class journals), and 3 monographs were published. The research achievements have reached the international advanced level in the corresponding field.
1. Using various genetic test stands that have reached or nearly reached the rotation age, the genetic laws of main economic traits of Pinus massoniana (such as growth and wood properties) were systematically revealed, including general combining ability (GCA)/special combining ability (SCA), additive/dominance/epistatic gene effects, paternal/maternal effects, heterosis, and inbreeding depression. A total of 182 new fast-growing and high-quality elite lines (provenances, families, clones, and hybrid combinations) were selected, with over 20% volume gain and 4% increase in wood density. Among them, 37 excellent families, 4 excellent clones, and 47 excellent individuals were officially approved, and 1 improved variety of Pinus massoniana second-generation seed orchard was certified.
2. A total of 320 second-generation breeding parents with fast growth and high quality were selected, and 4 second-generation breeding populations were established in the main breeding regions. The genetic variation and genetic diversity of the second-generation breeding parents were clarified, the molecular marker-assisted selection and heterosis prediction technologies for hybrid parents were established, 340 new third-generation breeding germplasms were created, which comprehensively promoted the advanced-generation breeding of Pinus massoniana.
3. Using second-generation parents with 30%–60% volume gain as orchard establishment materials, the construction technology of Pinus massoniana second-generation clonal seed orchards was resolved, which adopted large-specification container grafted seedlings in nurseries for one-time planting to form an orchard, as well as the "orchard-style" early fruiting and high-yield technology involving stem cutting dwarfing and pruning. A total of 2290 mu of new second-generation clonal dwarf seed orchards were established, which comprehensively promoted the upgrading of Pinus massoniana seed supply and afforestation with second-generation improved seeds.
4. The behavior and mechanism of effective soil phosphorus utilization and efficient acquisition of heterogeneous soil nutrients by Pinus massoniana were clarified. A specific index system for phosphorus efficiency of Pinus massoniana was established, the early identification and comprehensive selection technologies for high phosphorus efficiency genotypes were developed, and 21 excellent high phosphorus efficiency genotypes were selected, which enhanced the nutrient efficiency and high-yield characteristics of second-generation improved seeds on low-phosphorus infertile sites.
5. The rational layout of improved varieties (excellent provenances) of Pinus massoniana was determined, and the optimal allocation of improved varieties (excellent provenances) with main silvicultural measures including site conditions, phosphorus fertilizer application, and initial planting density, as well as the silvicultural technology for improving nutrient acquisition ability, were proposed.