甘蔗细茎野生种抗旱性与叶片持绿性生理生化机理研究

Yunnan province as the second major sugarcane-producing areas is facing its forth continuous drought year, new sugarcane varieties of drought-resistant are going to be needed more urgent than the past in sugarcane production . Stay-green as a measure of index of drought-resistance has been applied in lots of crops during the grain filling period. Genetic and physiological basis of stay-green already have been make a great progress. Comparing with crops which are harvested grain, the value of sugarcane is making of the sugarcane stalk yield and quality traits. Stay-green of sugarcane are difference in different varieties, systematic research reports on physiological and biochemical mechanisms, even their effects on yield and quality are very few. In this project, we will use F1 , backcross F 2（BC1）population of Yunnan S．spontaneum L as study material. By the strategy of sampling for pre-core collection of Sugarcane, the changes of biochemical criterion of the sugarcane, such as the numbers of physiological mature green leaves, average attenuation rate of green leaves area, cell protection enzyme activity, chlorophyll and Methane Dicarboxylic Aldehyde (MDA) will be measured by using artificial drought stress on those materials. Physiological and biochemical mechanism and genetic between drought tolerance of S．spontaneum L and stay-green will be researched by combing production and quality determination and analysis, we will find exploit effective methods of stay-green trait improvement resistance of sugarcane, which are important to raising the efficiency of sugarcane resistance breeding.

中国第二大甘蔗主产区云南的连年干旱，使得蔗糖产业对抗旱新品种的需求更为迫切。叶片持绿性作为衡量籽粒灌浆期抗旱性的指标，已在多种作物上得到应用。作物持绿性的遗传与生理基础研究亦取得很大进展。甘蔗品种间亦存在持绿性的差异，持绿性差的基因型，蔗糖分上升缓慢、峰值低，重力纯度不高，蔗汁榨出比低，相反，持绿性好的基因型，产量、品质表现优良。但甘蔗持绿性的生理生化机理及其对产量、品质的影响，尚缺乏深入研究。本项目按聚类分组，组内按对数比例，从云南不同生态型甘蔗细茎野生种及其杂交一、二代创新种质中选取研究材料，通过大生长期人工干旱胁迫与生理成熟期绿叶数、绿叶面积平均衰减速率、细胞保护酶活性、叶绿素和丙二醛含量等的动态监测，结合产量、品质测定与分析，系统研究甘蔗细茎野生种抗旱性与叶片持绿性的生理生化机理及其遗传，进而找到利用叶片持绿性改良甘蔗品种抗逆性的有效方法,这对提升甘蔗抗逆育种效率具有重要意义。

甘蔗细茎野生种抗旱性是甘蔗品种抗旱性的遗传基础，持绿性作为衡量籽粒灌浆期抗旱性指标，已在水稻、玉米等作物中广泛应用。本项目以云南不同生态型甘蔗细茎野生种F1、F2代共137份为研究材料，开展了2年新植1年宿根三重复随机区组试验；对其中83份参试材料不同程度水分胁迫下的持绿性、生长发育、生理生化指标进行动态监测；首次在甘蔗上利用持绿性评价抗旱性，并初步研究了持绿性与甘蔗产量、品质间的相关性，探索利用持绿性提升品种产量、品质的策略方法。. （1）筛选出了绿叶面积、+1-+6叶叶面积、7叶以下叶绿素含量等持绿性评价的关键指标，结合隶属函数、聚类、关联、回归分析等多指标综合评价方法的应用，建立了甘蔗持绿性评价的经验公式；（2）弄清了甘蔗细野生种F1、F2代持绿性和抗旱性的生理生化机理：随着水分胁迫程度的加剧，参试材料绿叶数减少，+1-+4叶叶绿素含量降低，抗旱性越强的基因型，叶片持绿性表现越好；甘蔗叶片的质膜透性（PMP）、丙二醛（MDA）含量、脯氨酸（P）含量、可溶性糖（SS）含量、过氧化物酶（SOD）活性和超氧化物歧化酶（POD）活性升高，叶绿素（CHL）含量和可溶性蛋白（PRO）含量降低，各指标变化幅度大小因甘蔗基因型差异及水分胁迫程度不同而不同，且云南甘蔗细茎野生种F1代较F2代表现更强的抗旱能力；（3）验证了持绿性作为甘蔗抗旱性评价指标的可行性，建立了叶绿素含量、绿叶数与总叶数比值预测甘蔗抗旱性的经验公式，大大提高了抗旱性鉴定效率，为大量种质材料的抗旱性鉴定奠定了方法基础；（4）找到了持绿性与甘蔗产量、品质间的关键指标。持绿性与甘蔗产量、品质间相关性研究表明持绿性与产量极显著正相关，与锤度负相关；但+1-+6叶叶面积与产量、锤度均极显著正相关，这将有可能为利用持绿性提升甘蔗产量、品质提供有效途径；（5）项目实施发表论文18篇，培养硕士研究生3名，课题组成员4人晋升职称，按计划完成了各项预期目标。