【作者】 范文丽；

【导师】 李天来；

【作者基本信息】 沈阳农业大学 ， 蔬菜学， 2015， 博士

【摘要】 长白楤木(Aralia continentalis Kitagawa)为五加科楤木属多年生食药兼用草本植物,是东北地区著名山野菜,但因过渡采集利用,其野生资源数量和质量急剧降低。近年来为保护和高效开发资源,长白楤木的人工栽培需求不断增加,扩大栽培规模所需的优质秧苗数量巨大。由于受制于种子休眠因素的影响,培育长白楤木优质秧苗成为产业发展的关键限制因素。为此,本文采取野外调查、室内化验与田间试验相结合的方式,对影响长白楤木种子质量因素进行分析,并对长白楤木种子休眠影响因素及种子休眠解除过程物质代谢变化及环境刺激引起一系列的生理生化反应进行了系统研究。以期为长白楤木种苗繁育过程中种子精选、种子休眠解除、培育优质种苗提供参考。主要试验结果如下：1.通过辽宁、吉林和黑龙江三不同生态区5个采种点种子质量影响因素的相关分析,明确了有效积温是影响长白楤木种子发育的主要因素,有效积温达到553.7-1147℃为花期,有效积温达到1029-1586℃为结果期；有效积温达到1438-1810℃为种子采收期。繁种基地应选择积温高、光照充足,降雨偏少的地区。在满足这些条件地区采集的种子出胚率高、休眠程度低、种子后熟快,种子萌发率高。在沈阳地区采种适宜时间为8月30日到9月10日,且同一植株以顶花序形成的种子质量最好。2. NaCl溶液能够对种子进行有效精选,10% NaCl溶液浸泡6h种子沉降率可达50%,沉降的种子质量好,发芽整齐度高,萌发率高达91.8%,为长白楤木种苗繁育提供了保障。3.明确了长白楤木种子休眠的原因,长白楤木种子种胚未发育完全,种子内含有抑制萌发的酚类物质,且成熟长白楤木种子内高浓度的ABA和低浓度的GA3也促进了长白楤木种子的休眠,因此长白楤木休眠程度深。对新采收的长白楤木成熟种子的解剖观察显示,种胚很小,囊泡状,透明,椭圆形,内呈液态,胚乳呈胶状,有弹性。种胚未发育完全,胚后熟在不同程度没有完成,其浆果、种皮及胚内均含有酚类抑制萌发物质,且主要存在于胚内,种皮虽对种子吸水有一定的障碍,但不影响其吸水效果,因此长白楤木种子为形态后熟型综合性休眠。4.明确了自然贮藏12个月可以有效解除休眠。因为贮藏为长白楤木种胚发育提供了时间, 随贮藏时间延长长白楤木种子内相关物质代谢与转化加强,总酚含量降低,淀粉酶、POD酶和G-6-PDH被活化,促进种子休眠解除,自然贮藏12个月种子休眠可解除。贮藏6个月种胚发育迅速,贮藏12个月种子内酚类物质显著降低,种子内0[-淀粉酶活性、α+β淀粉酶活性增强,有效调动种子内物质的代谢,为种子萌发积聚能量。贮藏12个月时也是种内各激素浓度跃变关键期,种子内GA3含量的迅速升高,ABA含量迅速降低,IAA含量缓慢下降,GA3/ABA比值升高迅速,而IAA/ABA、ZR/ABA比值的变化趋势一致,均在贮藏12个月时达最大值,种子解剖观察也证实种胚已发育完全,种子休眠解除。5.采取变温层积处理可加速长白楤木种子休眠解除,主要通过加速种胚发育进程,增加营养物质分解酶和呼吸代谢途径关键酶活性,调控种子内激素含量及平衡关系而加速种子休眠解除,5/25℃变温层积处理30d即可有效解除种子的休眠。5/25℃变温层积处理加速了长白楤木种胚发育进程,裂口速度快,处理10d后种胚变化明显,种胚子叶、胚根分化和生长均比5℃和10℃恒温处理早10-20d,胚乳乳化速度快,处理30d种子萌发率达25.3%。6.研究了硫酸、H2O2、NAA及GA3对长白楤木种子休眠解除效果,发现外源GA3对解除长白楤木种子休眠效果更显著,外源GA3可加速种子内物质代谢速度,降低萌发抑制物质浓度,调控种子呼吸EMP-TCA途径及PPP途径相关酶活性及种子内源激素平衡而解除种子休眠的。长白楤木种子内总酚含量随GA3处理浓度的升高而降低,随处理时问延长而降低；50 mg·L-1、150 mg·L-1 GA3处理种子内总酚含量下降幅度较大,对种子处理效果较好。在本试验范围内,150 mg·L-1的GA3处理发芽率最高为51.83%,15-19 d发芽势较高。7.变温层积条件下,外源150 mg·L-1 GA3处理更有利于解除长白楤木种子休眠,处理20d时种内GA3含量急剧上升,ABA含量下降最快,IAA和ZR含量变幅较小,GA3/ABA随层积时间增加而增加迅速,而IAA/ABA、ZR/ABA随层积时间增加而缓慢下降,与种子胚发育相比对,在种子体眠解除期(30d)时正是种胚快速生长期,因此变温层积过程中外源GA3处理可显著调动种子内GA3积累,显著降低ABA含量,二者共同作用起到了解除长白楤木种子休眠的作用,为胚的萌发做准备。8.建立了长白楤木种苗繁育体系。选择有效积温1670℃以上地区(沈阳)建立长白楤木种子繁育基地,按照长白楤木物侯期选留顶花枝作为主要结果枝,去掉最早开花和较晚开花的花枝,在9月左右适时采收。采收后的种子用10%NaCl进行精选,然后用150 mg·L-1 GA3溶液浸种、5/25℃变温层积处理,处理30d后即可催芽播种,播种后10d即可出苗,30d即可成苗。更多还原

【Abstract】 Aralia continentalis Kitagwa belongs to family Araliaceae which is a renowned perennial wild edible herbs in Northeast of China due to its exceptional nutritional and medicinal value. However, the quantity and quality of Aralia continentalis Kitagwa is dramatically reduced by over-exploitation. Artificial cultivation of Aralia continentalis Kitagwa is gradually increased in recent years to effectively protect and exploit the resource. A large number of Aralia continentalis Kitagwa seedlings are needed for artificial cultivation, whereas high quality seedlings of Aralia continentalis become a key factor limiting the development of Aralia continentalis Kitagwa industry due to seed dormancy. In this study, we focus on the factors that affect seed quality and seed dormancy. In addition, metabolism changes in seed dormancy and environmental stimulation are conducted by physiological andl biochemical reactions. Our results will lay a solid foundation for gaining better seeds, removing seed dormancy and developing seedlings with high quality for Aralia continentalis.The results are as follows:1. Effective accumulated temperature was the main factor affecting seed development of Aralia continentalis Kitag through correlation analysis of the factors influencing seed quality in different ecological areas(Liaoning,Jilin,Heilongjiang). An effective accumulated; temperature of 553.7-1147℃ was defined as flowering; an effective accumulated temperature of 1029-1586℃ was defined as fruiting period; an effective accumulated temperature of 1438-1810℃ was defined as seed harvest period. The region with high accumulated temperature, adequate light and low rainfall was beneficial to obtain the seeds with high level of embryo quality, low seed dormancy, rapid seed ripening and high rate of seed germination. August 30th to September 10th was suitable for Shenyang city and seeds in top inflorescence were with high quality compared with other parts of the whole plant.2. NaCl solution is effective for seed selection. The rate of seed sedimentation could be up to 50% by 10% NaCl solution treated 6h. These seeds were with good quality and high uniformity of germination and the rate of germination was up to 91.8%. These data provided an important information for the breeding of Aralia continentalis seedling.3. The embryo of Aralia continentalis was not fully developed and phenolic compounds in seeds inhibited the germination of embryos. In addition, high concentrations of ABA and low concentration of GA3 were also responsible for the dormancy of the new seeds of Aralia continentalis, which resulted in the deep dormancy of Aralia continentalis Kitag seeds. Anatomical observation of new mature seeds revealed that embryo was small, vesicular, transparent, oval and liquid and the endosperm was gelatinous and elastic. Therefore, the seed mature and embryo post-maturation were not totally finished. The bacca, seed coat and embryo included phenols which inhibited seed germination, especially in embryo. Seed coat had certain obstacles on water uptake, whilst this did not affect the effects of water uptake. So, Aralia continentalis seed was morphophysiological dormancy.4. Storage was helpful for the development of Aralia continentalis embryo. The metabolism and transformation of Aralia continentalis Kitag seeds were enhanced. Total phenolic content decreased, the activity of amylase and peroxidase (POD) and G-6-PDH were activated with increased storage time, which accelerated the remove of seed dormancy.12 months natural storage could remove seed dormancy.Phenolic compounds significantly decreased after 12 months storage. The activity of a-amylase and a+(3 amylase was improved which promoted material metabolism and accumulated energy for seed germination. The content of GA3 was rapidly increased, while the content of ABA was quickly decreased and the content of IAA was slowly decreased. Moreover, the ratio of GA3/ABA was dramatically enhanced, whilst the change trend of ZR/ABA and IAA/ABA was consistent. Seed anatomy observation also confirmed that the embryo developed completely and the seed dormancy was relieved.5. Alternating stratification contributed to seed dormancy release through accelerating the development of the embryo, increasing the activity of nutrients decomposing enzymes and respiratory metabolism pathway key enzymes, regulating hormone content and balance in seeds. The seed dormancy was relieved at 5/25℃ alternating stratification for 30d, which accelerated embryo developmental process of Aralia continentalis Kitagwa. The change of embryo was significantly after 10d treatment at 5/25℃ alternating stratification and the differentiation and growth of cotyledon and radicle were earlier 10-20d than 5℃ and 10℃ stratification.6. Effect of Exogenous GA3 on the seed dormancy of Aralia continentalis Kitagwa was remarkable. Exogenous GA3 could accelerate seed metabolism speed, reduce germination inhibitory substance concentration, regulate related enzyme activity of seed respiration EMP-TCA and PPP pathway and maintain seed endogenous hormones balance. The total phenolic content of Aralia continentalis Kitag seeds decreased with increased GA3 concentration and the prolonged treatment time.50 mg·L-1 and 150 mg·L-1 GA3 treatment could greatly decreased total phenols contents. In this study, the highest germination rate was 51.83% and the higher germination potential was 15-19 d with the treatment of 150 mg·L-1GA3.7. Seed dormancy of Aralia continentalis released rapidly with alternating stratification and 150mg·L-1 GA3 treatment. Treated 20d, GA3 content sharply increased; ABA content greatly decreased; IAA and ZR content changed very little; GA3/ABA increased quickly and IAA/ABA, ZR/ABA decreased slowly with the prolongation of treatment time. Compared with seed embryo development, the dormancy period (30 days) was a rapid growth period for embryo. Therefore, the application of exogenous GA3 treatment could stimulate the accumulation of GA3 and significantly decrease the content of ABA, both of them released seed dormancy for embryo germination.8. The establishment of Aralia continentalis breeding system.The effective accumulated temperature for the breeding base should be more than 1670℃. Top flower branches should be obtained and get rid of the early flowering and late flowering branches based on phenological phase of Aralia continentalis. Harvest time is around September. The dry seeds should be selected before germinating and treated with 10% NaCl solution for 6h. The treated by10% NaCl and located in lower layer seeds were treated by 150 mg.L-1GA3 for 2h, then these seeds were placed on 5/25℃ alternating stratification for 30d. seedings will be got after 10 days germinating and the seedlings are uniform and with good quality. Excellent seedlings can be obtained about 30 d.更多还原