糯玉米单倍体诱导和加倍的研究

Haploid inducing and doubling of waxy maize

【目的】探索单倍体诱导系在糯玉米单倍体育种应用中的可能性及适宜的糯玉米单倍体诱导和加倍方法,以加快我国糯玉米育种进程,提高糯玉米育种效率。【方法】诱导试验中以吉林农业大学选育的5个诱导系(HG1-HG5)作为诱导材料对不同糯玉米母本材料进行诱导,比较不同花丝长度、授粉时期和果穗部位对糯玉米单倍体诱导率的影响;加倍试验中,以秋水仙素作为糯玉米单倍体人工染色体加倍药剂,采取4种(浸种法、浸芽法、滴心叶法、针刺生长点法)处理方法,每种方法设置3个秋水仙素质量浓度梯度(0.3,0.5和0.7mg/mL)并辅以2.5%二甲基亚砜(DMSO)作为助渗剂,筛选适宜的糯玉米单倍体加倍方法。【结果】诱导试验结果表明,延迟授粉(花丝长度≥8cm)单倍体诱导率均值为17.9%,约为正常授粉(花丝长度≤4cm)条件下的2.9倍;伏后授粉单倍体诱导率均值为19.4%,约为伏期授粉的3.1倍;果穗顶部的诱导率(6.87%)高于底部(5.61%)。加倍试验结果表明,浸种法对植株伤害较严重,存活率低于50%;针刺生长点法(0.7 mg/mL)和滴心叶法(0.5 mg/mL)的散粉率较高(45.9%,28.9%),相应的结实率也较高(15.2%,11.1%),说明针刺生长点法处理效果最好,滴心叶法次之。【结论】糯玉米单倍体育种能提高糯玉米育种效率。

【Objective】The possibility of applying haploid inducing lines in breeding of waxy maize and the suitable inducing and doubling methods were investigated to accelerate the breeding process and improve the breeding efficiency of waxy corn in China.【Method】Waxy maize haploid inducers（HG1-HG5）released by Jilin Agricultural University were used as male parents to conduct maize haploid inducing test.Waxy maize inducing rates were compared among silk length,pollinating date and parts of ears.Colchicine was used as doubling agent of waxy maize haploid artificial chromosome,2.5% DMSO was used as an auxiliary agent,and four approaches（dipping seed method,dipping bud method,dipping heart leaf method,and acupuncturing growing point method）and three concentration gradients（0.3,0.5and 0.7mg/mL）were tested to select suitable doubling method.【Result】The haploid inducing rate of long silk（≥8cm）pollination was 17.9% on average,almost 2.9times of short silk（≤4cm）pollination.Haploid inducing rate of late summer pollination was 19.4% on average,about 3.1times of mid-summer pollination.Haploid indu-cing rate on top of ear（6.87%）was higher than that in bottom（5.61%）.Dipping seed and dipping bud methods had the survival rates of less than 50%.Fertile rates of acupuncturing growing point method at0.7mg/mL and dipping heart leaf method at 0.5mg/mL were 45.9%and 28.9%and their seed rates were15.2% and 11.1%,respectively.Acupuncturing growing point method was the best followed by dipping heart leaf method.【Conclusion】Application of haploid breeding may improve breeding efficiency of waxy maize.