苏铁属花粉萌发及保存条件研究

以不同浓度梯度的蔗糖与硼酸组合在不同pH条件下用悬浮培养法测定德保苏铁、叉叶苏铁、元江苏铁和越南篦齿苏铁花粉的活力;将元江苏铁和越南篦齿苏铁花粉分别保存在不同低温、不同湿度的环境中,研究温度和湿度对保存花粉的影响。结果表明:(1)最适合苏铁属植物花粉萌发的培养液配方为蔗糖(1%～2.5%)+硼酸(100～500 mg/L),pH6.0～7.0;(2)在室温下,将苏铁花粉密封保存在有干燥剂的容器中,可存活30 d以上;(3)在0℃条件下,不加干燥剂,花粉可保存4个月以上;(4)用液氮保存后的越南篦齿苏铁花粉进行人工授粉,结实率高达90.3%,与用新鲜花粉人工授粉的结实率无明显差异;(5)将花粉含水率降低到15.5%～13.2%后,能在液氮中进行长期保存,表明花粉液氮保存可以作为苏铁花粉长期和超长期保存的方法。

Studies on pollen germination and storage of Cycas species

Pollen suspension culture was conducted under combinational conditions of different grades of pH and concentrations of sucrose and boric acid to estimate pollen viability of Cycas debaoensis,C.bifida,C.parvulus,C.eloneata. Pollen viability of C.parvulus and C.elongata was also estimated after being stored in different temperature and humidity conditions.The results showed that:(1)the optimal medium for the germination of those cycad's pollen was compose of 1%—2.5%sucrose+100-500 mg/L boric acid and pH was in the range of 6.5—7.0;(2)the pollen stored in a sealed container with desiccant in room temperature was viable up to one month;(3) the pollen being stored under 0℃in a container without desiccant could kept its viability over 4 months;(4)through artificial pollination, the seed setting rate of C.elongata could be up to 90.3%by using liquid nitrogen stored pollen,which is no remarkable difference to those of using fresh pollen;(5)the pollen of C.elongata,after stored in liquid nitrogen for period of time,did not show significant loss of viability after dried to 13.2%—15.5%of water content and the results indicated that stored in liquid nitrogen can be used as a long term storage measure for cycad pollen.