甘蔗试管苗瓶内生根与瓶外生根培养方法比较研究

以新台糖22号（ROC22）甘蔗无根试管苗和有根试管苗为材料,对其移栽苗圃后成活率、分蘖率、株高、根系生长情况及两种试管苗生根成本进行了研究。结果表明：两种生根法各有优劣;传统的瓶内生根技术有利于组培苗的生根,提高了苗的生根率、长势和移栽成活率及苗的质量;瓶外直接生根则有利于降低甘蔗组培的生产成本,提高组培苗的产量和缩短苗的生产周期。     

干旱胁迫对苗期甘蔗叶片水分和叶绿素荧光参数的影响

[目的]研究干旱胁迫对甘蔗叶片水分和叶绿素荧光参数的影响,为甘蔗生产及评价研究提供依据.[方法]选取7个抗旱性不同的甘蔗品种,在苗期进行干旱胁迫,并测定胁迫条件下甘蔗叶片水分含量和叶绿素荧光参数的变化.[结果]甘蔗叶片水势和相对含水量与土壤相对含水量存在一定的内在联系,耐旱强的品种对土壤水分的利用率较高;相关分析和因子分析表明茁期干旱存活率、Fc/Fm、叶片水势和相对含水量可被用作抗旱性评价指标.[结论]水势表现为一个相对独立的影响因子,对甘蔗抗早性有支配作用,并验证了Fv/Fm作为甘蔗抗旱评价指标的可靠性. Abstract： [Objective] The aim was to explore the effects of water stress on leaf water and chlorophyll fluorescence parameters of sugarcane seedling,as well as to provide basis for the study on sugarcane production and evaluation.[Method]Seven different sugarcane varieties were studied at the seedling stage under drought stress,and the changes of leaf water and chlorophyll fluorescence parameters under stress conditions were detected. [Result] leaf water potential,leaf relative water content and soil relative water content showed a certain amount of internal relationship,the sugarcane varieties that had more tolerant to drought had higher utilization rate of soil water;the correlation analysis and factor analysis suggested that the survival rate at seedling stage under drought stress,Fv/Fm,leaf water potential and relative water content could be used as drought resistance evaluation indicators. [Conclusion] As a relatively independent influencing factor,water potential had dominating effect on drought resistance,and the reliability of Fv/Fm as drought resistance evaluation indicator had been verified.     

镉胁迫条件下硅对果蔗幼苗生理生化特性的影响

采用砂培试验,以广西普遍种植果蔗品种(Badila)为材料,研究不同质量浓度Si(0、10、20、40 mg/L)对Cd胁迫条件下果蔗生理生化指标的影响,以期进一步揭示Cd胁迫下Si对果蔗毒害的缓解机制,为合理利用Si缓解重金属对植物的毒害提供科学依据。在Cd胁迫下,果蔗幼苗超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量、脯氨酸(Pro)含量升高,叶绿素含量降低。施用外源Si能降低Cd胁迫下果蔗幼苗SOD活性,Si质量浓度为40 mg/L时,效果最明显;能降低Cd胁迫下果蔗幼苗CAT活性及MDA、Pro含量,Si质量浓度为10 mg/L时,效果最明显;能提高Cd胁迫下果蔗幼苗的叶绿素含量,Si质量浓度为20 mg/L时,效果最明显。综上,适当质量浓度的外源Si能在一定程度上减轻重金属Cd胁迫对果蔗幼苗的伤害。     

干旱霜冻条件下甘蔗耐寒性评价

[目的]为了解干旱霜冻条件下甘蔗性状变化特点与评价品种耐寒性。[方法]选用国内外21个甘蔗品种（系）在广西霜冻常发区资源县开展了耐寒性评价试验。[结果]轻霜冻前后的甘蔗锤度、绿叶数和光合速率发生明显变化,且耐寒性差的品种下降较多,但仅有重霜冻后的茎长冻损率、节间冻损率、绿叶百分率与轻霜冻后的锤度和锤度变化相关;进一步分析发现,选用茎长冻损率、上位叶绿叶百分率进行甘蔗耐寒性评价更为简单易行。耐寒性评价表明,在南亚热带和热带地区选育甘蔗品种,如果未经过耐寒性鉴定,选育的新品种其耐寒性表现好和较好的机率将低于30.0%,而表现差和较差的机率将高于60.0%。[结论]为甘蔗耐寒评价和选育耐寒品种提供了依据。