钩苞大丁草的遗传多样性评价及优异纤维种质发掘

The natural cellulose fibres from abaxial side of fireweed (Gerbera delavayi) leaf blade, the shortest of natural textile fiber, is the material of fireweed clothes by minority people using manual twisting and weaving in southwest China, At present, the unique fireweed textile techniques have been included in the intangible cultural heritage of Yunnan and Sichuan Province. Previous research found that Gerbera delavayi has not yet to be cultivated by people. Its wild resources have been severely damaged and need protective exploitation urgently. Therefore, in this project, the nursery of Gerbera delavayi will be established by 11 populations. And then the genetic diversity and genetic structure of Gerbera delavayi will be evaluated by morphology, cell ploidy, genic-SSR and genic-SNP molecular markers based on transcriptome data (have been obtained), ISSR molecular markers, and cpDNA rbcL and trnL-F sequence analysis. At the same time, the fiber properties, twisting efficiency, and line quality (twist, etc.) of each sample will be evaluated. And then excellent fibre germplasm will be screened based on the abovementioned evaluation, and plant morphology and cell ploidy. This project will provide scientific basis for the strategy making in protective exploitation of Gerbera delavayi, and excellent propagule for the artificial cultivation of Gerbera delavayi. The project will is of great significance to inherit and carry forward the intangible cultural heritage -- fireweed textile technology.

钩苞大丁草又名“火草”，其叶背毡毛纤维是我国西南少数民族人民用于手工捻线然后编织成火草服饰的原料，是迄今最短的天然纺织纤维。目前，独特的火草纺织技艺已被列入云南省和四川省的非物质文化遗产。前期调研发现，钩苞大丁草尚未实现人工种植，其野生资源已遭到严重破坏，亟待保护性开发。为此，本项目将建立由11个钩苞大丁草居群构成的资源圃，然后利用植株形态、细胞倍性、基于转录组数据（已获得）开发的genic-SSR与genic-SNP分子标记、ISSR分子标记和cpDNA的rbcL与trnL-F序列分析，阐明钩苞大丁草的遗传多样性及遗传结构。同时，对各样本的纤维特性、捻线效率与纱线品质（捻度等）进行评价，并结合植株形态和细胞倍性，筛选优异纤维种质。项目的实施，将为制定钩苞大丁草的保护性开发策略提供科学依据，为钩苞大丁草的人工栽培提供优质种源，对非物质文化遗产——火草纺织技艺的继承和发扬具有重大意义。

钩苞大丁草（Gerbera delavayi）又名“火草”、“火石花”，其叶背毡毛纤维是我国西南少数民族人民编织火草服饰的原料。火草线的获得是从鲜叶叶被直接剥离并同时捻线，这项特殊的纺织技艺已有500多年的历史，被列为国家级非物质文化遗产。然而，火石花尚未实现人工种植，其野生资源已遭到严重破坏，亟待保护性开发。.遗传多样性研究是火石花保护性开发的重要依据，而分子标记是揭示遗传多样性最理想的方法。为此，本项目建立了9个居群204个植株构成的资源圃。并且，开发了火石花的Genic-SSR分子标记，选用19对引物进行遗传多样性及遗传结构分析。结果共检测出154个等位基因位点，平均每个位点等位基因数目为8。有效等位基因（Ne）总数为44.7307，平均每个位点有效等位基因数目为2.2365。观测杂合度（Ho）和期望杂合度（He）的均值分别为0.3049和0.4649。9个野生群体的平均遗传多样性偏低（Ne=2.0548）。9个野生群体的近交系数（Fis）平均值为0.2617，表现为纯合子过剩。群体内基因交流频繁（89.03%的遗传变异存在于群体内部），但群体间分化不明显（10.97%的遗传变异来自于群体间）。ITS和叶绿体的rbcL与trnL-F序列均表明：PE与其它群体间存在较为明显的遗传分化，而其余的8个野生群体的基因库较为均匀。综上，9个野生火石花的群体遗传一致性较高，遗传多样性不是很丰富。.钩苞大丁草叶背纤维的化学成分与棉相似，其蜡质含量高出棉的四倍。钩苞大丁草纤维表现出极低的长度(3-8 mm)、细度(0.3-0.5 dtex)、弱韧性(0.5-0.6 cN/dtex)、密度(0.9 g/cm3)和结晶度(14.6%)，但其断裂伸长率、回潮率与棉类似。此外，钩苞大丁草纤维拥有光滑的表面、柔软的质地，还有不浸润水的特性。共筛选出优异纤维种质7份。.该研究将为火石花的保护性开发提供科学依据，对非物质文化遗产——火草纺织技艺的继承和发扬具有重大意义。