白魔芋多倍体诱导研究初报

采用种子浸泡法和根状茎顶芽滴液法进行白魔芋多倍体诱导，比较了不同秋水仙素浓度和不同处理时间对出苗率和变异率的影响。结果表明，滴液法对材料的毒害性更小，经同一浓度秋水仙素溶液处理后出苗率和植株形态变异率均高于种子浸泡法，但诱变加倍的效果不如浸泡法。实验中获得一株纯合四倍体植株，由0.20%秋水仙素溶液处理种子48h诱变得到。     

不同秋水仙素处理方法对罗汉果植株变异的影响

以二倍体罗汉果永青1号为研究材料,用0.05％、0.1％、0.2％三种不同浓度的秋水仙素对其进行滴生长点、浸种处理、定量注射法及涂抹法诱导多倍体.结果表明:滴生长点法诱变效果最好,诱变率可达24.3％,而定量注射法成活率为0,涂抹法诱变率为0.与正常植株相比,变异植株在前期生长缓慢,但中后期生长比较旺盛,植株形态有明显的改变,经染色体鉴定为多倍体.     

人工诱变芦荟多倍体的初步研究

以秋水仙索为诱变剂，利用茎段浸泡和秋水仙素培养基2种方法对库拉索芦荟进行诱变，结果表明，茎段浸泡秋水仙素法诱导四倍体葡萄的效果优于秋水仙素培养基法，0．2％的秋水仙素处理4d变异效果最好，诱变率达到最高值41.5％。变异株叶片肥厚，叶色深绿，叶片表皮气孔保卫细胞中叶绿体数增多。     

秋水仙素浸芽法处理玉米单倍体的加倍效果研究

试验采用28个育种材料的玉米单倍体籽粒,使用0.06%秋水仙素溶液浸泡幼芽上部和幼芽全部,研究秋水仙素对玉米单倍体的加倍效果的影响。结果表明,3年中不同秋水仙素浸芽方法处理玉米单倍体的成活率、授粉率和结实率之间的差异达到显著或极显著水平。浸泡幼芽上部处理能够明显减轻药害,缩短缓苗时间,提高单倍体植株的加倍效果,成活率、授粉率和结实株率均是浸泡幼芽全部处理的1.5倍左右,而且浸泡幼芽上部处理的授粉率和结实率分别是对照的2倍和4倍以上。     

青檀多倍体诱导试验初报

为获得具有优良性状的青檀四倍体植株,以青檀幼苗为试验材料,通过秋水仙素浸泡生长点的方法,研究了不同秋水仙素浓度和处理时间对青檀染色体加倍的诱导效果。结果表明：以0.4％—0.8％秋水仙素处理72ｈ诱导效果最佳,变异率最高达34.2％。经流式细胞仪和茎尖染色体鉴定,初次镜检青檀四倍体植株染色体数目为2n＝4x＝36,成功获得了青檀四倍体植株。     

秋水仙素诱导乌拉尔甘草同源四倍体的研究

在组织培养条件下,用秋水仙素溶液浸泡乌拉尔甘草试管苗(2n=2X=16)茎尖进行同源四倍体诱导,比较了不同秋水仙素浓度和不同处理时间对存活率、变异率的影响,并对加倍植株的鉴定和纯合四倍体的分离方法进行了研究.结果表明,秋水仙素浓度为0.1%,浸泡时间为12h时,茎尖的存活率和变异率分别为52.3%和22.1%,诱导率较高,并通过保卫细胞和根尖染色体数目鉴定,成功获得了甘草同源四倍体(2n=4X=32),为开展甘草多倍体育种奠定了物质和技术基础.     

冬小麦花药愈伤组织无性系株高遗传研究

从Ｈ１花药单倍体试管苗基部，取尚未分化绿苗的胚性愈伤组织建立的体细胞无性系，获得４丛Ｒ１结实株系。从田间Ｒ２的观察中发现，Ｒ１的４株后代中有１株４个穗繁衍的８６个单株发生了变异，Ｒ２的株系变异率为２５％。经过这株变异的Ｒ２、Ｒ３的株高连续观察发现：株高变异范围均很大，并有超亲现象，Ｒ２的变异大于Ｒ３；穗系间和穗系内的变异均极显著，穗系间变异大于穗系内变异；Ｒ３有８．１４％的株系已稳定；Ｒ２和Ｒ３的     

秋水仙素诱导小豆性状变异研究

本研究用0.2%和0.4%的秋水仙素溶液浸泡小豆京农6号(JN6)种子12 h,M_1成株率分别为26.7%和3.5%,变异率为1.24%和1.59%,结果表明处理浓度越大,成株率越小、变异率越大.0.2%秋水仙素处理12 h为较佳处理,但0.4%处理的变异类型相对丰富.M_2代与对照相比,单株粒数在5%水平上达到显著差异,百粒重在1%水平达到极显著差异;M_3代百粒重与对照相比在1%水平达到极显著差异,诱变后代中筛选出了3个高产优良株系.在M_3代共筛选到263个叶色、叶形、蔓生、多分枝、黑荚、浅红和深红粒色、大粒及早晚熟等性状变异突变体.叶形有剑叶、小密叶、肾叶突变类型;叶色有深绿、浅绿、黄化、黄斑叶变异类型.早熟和晚熟变异株分别比对照早熟10～15 d和晚熟7～10 d.     

影响组织培养诱导四倍体小果型西瓜三种因素的研究

以二倍体小果型西瓜自交系21，90，141，149,157的授粉后20～25d的未成熟种子中的子叶为材料，进行离体组织培养诱变四倍体，研究了不同的秋水仙素浓度、处理时间对组织再生，不同的秋水仙素浓度、处理时间与再生途径对加倍率的影响。结果表明，未成熟子叶组织再生有产生单芽、芽丛、愈伤组织3种方式；不经秋水仙素诱导处理，直接进行组织再生时，直接再生不定芽能力强；经秋水仙素诱导处理后，进行组织再生时不定芽产生受到抑制，愈伤组织发生数多于单芽或芽丛数；基因型不同，处理的秋水仙素浓度与时间不同，再生的组织类型与数量不同；还发现经一定时间的适宜浓度的秋水仙素处理后，有利于产生的愈伤组织分化成苗；对再生植株鉴定可知，0．03％秋水仙素处理9d或0．05％秋水仙素处理7d可诱导出较高比例的四倍体植株，并且通过愈伤组织途经的加倍率高于通过单芽和芽丛途经。     

秋水仙素浓度、浸苗时间对烟草单倍体幼苗的加倍效应研究

为了提高烟草单倍体植株的染色体加倍率,采用二次饱和D-最优设计,以两片真叶期的烟草单倍体幼苗为材料,研究了秋水仙素浓度及其浸苗处理时间对染色体加倍的效应.结果表明,随着秋水仙素浓度的提高,加倍率呈开口向下的抛物线曲线变化趋势;加倍率与浸苗时间呈线性回归关系,加倍率随浸苗时间的延长而增加;0.346 9%的秋水仙素、浸苗72 h是烟草单倍体幼苗染色体加倍率最高(达54.18%)的最佳处理组合.     

Induction and identification of hexadecaploid of <Emphasis Type="Italic">Pinellia ternate</Emphasis>

Pinellia ternate (Thunb.) Breit (Araceae) is an important Chinese medicinal herb. In order to obtain the hexadecaploid plants of P. ternate with improved medicinal qualities, the shoot tips from in vitro-grown plants were treated with colchicine at various concentrations for different time to double the chromosome number. We obtained highest (42.5%) frequency of morphological variation when the tips were treated with 0.1% colchicine for 48 h. The putative hexadecaploid plants showed characteristics such as larger and thicker leaves, deeper green leaf color, stouter petiole, larger stomata, lower density of stomata across the lower epidermis of leaves and increased numbers of chloroplasts per stomata guard cell. Further analysis by flow cytometry and chromosome counting confirmed seven out of 129 were hexadecaploids. Besides, the growth rate (GR) of PLBs in hexadecaploid plants was 10.49% (increase rate in 1 day), 1.6 times higher than that of octoploid plants and the alkaloid content of PLBs in hexadecaploid plants was 0.0794%, 1.8 times higher than that of octoploid plant. The results indicated that we have established a successful procedure for development and propagation of hexadecaploid of P. ternate with higher GR and alkaloid content.     

Efficient Production of Doubled Haploid Plants through Chromosome Doubling of Isolated Microspores in Brassica napus

Three methods of chromosome doubling to produce doubled haploid plants from microspore cultures of Brassica napus were compared: colchicine treatment of microspore-derived plants, microspore-derived embryos, and isolated microspores. In the whole plant treatment, 53% of the treated plants set seed, but the treatment delayed plant growth and reduced seed set. When microspore-derived embryos were treated with colchicine, the doubling frequency was 32% (compared to 15% for spontaneous doubling). Direct colchicine treatment of isolated microspores resulted in a doubling efficiency of 70 % of the whole plants. This treatment also stimulated embryogenesis in microspore culture, leading to increased plant regeneration. Thus, direct chromosome doubling of isolated microspores is efficient and more than 10 000 doubled haploid plants have been produced in this manner in the past three years in order to accelerate the plant-breeding process.     

In vitro induction of tetraploids in Phlox subulata L.

Tetraploid plants of Phlox subulata L. were induced successfully by treating shoot tips in vitro with colchicine. Shoot tips excised from in vitro shoots were treated with four different concentrations of colchicine (0.005, 0.01, 0.02, 0.04%) in solid MS medium supplemented with 4.54 μM TDZ and 0.49 μM IBA for 10, 20 or 30 days, respectively. The survival rates of shoots tips were affected by the concentration of colchicine and the duration of treatment. High concentration and longer duration reduced survival of the shoot tips, but the effect of duration of colchicine was more than that of concentration. Tetraploid plants were obtained in all of the treatments, but the percentages of tetraploids varied among different treatments, from 25.0% to 75.0%. The most efficient condition for inducing tetraploids was to treat shoot tips with 0.005% colchicine for 20 days, with 30.0% survival rate of shoot tips and 6 tetraploid plants out of 10 plants examined. The rooted tetraploid plants were transplanted successfully in a solar greenhouse. Under the same growing condition, significant varieties in flower bud and flower sizes were detected between 2x and 4x plants. The flower diameters of tetraploid and diploid plants were 2.91 cm and 2.24 cm, respectively.     

春蚕豆再生植株遗传变异鉴定研究

对继代6代的蚕豆的再生植株的遗传变异进行田间鉴定、籽粒形态鉴定和DNA分子标记鉴定,结果表明:在田间对株型、叶色、茎色、花色、荚色进行鉴定均没有发现变异;对籽粒形态的鉴定中仅有1%的粒色和0.5%的脐色变异;利用AFLP技术对发生农艺学性状变异的组和未发生农艺学性状变异的组进行检测,没有检测到变异;说明在继代6代时,未检测到在基因组水平上发生变异。     

Chromosome doubling of mature haploid Brussels sprout plants by colchicine treatment

Summary The effect of colchicine concentration, and the mode and time of colchicine application in doubling the chromosomes of haploid Brussels sprout plants was assessed by scoring treated plants for the presence of diploid flowers and seed set after self-pollination.When colchicine treatments were applied after the plants had been vernalised, using 2 dose rates and 3 methods of application, only 38.1% became doubled and only 13.8% produced seed. Treatment with 0.1% colchicine with or without the addition of 2% dimethyl sulphoxide gave doubling rates similar to those reached with 0.05% colchicine, but resulted in more damage to the apices.When 0.05% colchicine solution was injected into the plants' apices at varying times during vernalisation, the rate of doubling was 71.2% on average and 50.7% of plants gave seed on selfing.Overall doubling rates of plants where the apex was easily accessible were 79.0%, while for plants with dense terminal heads they were 35.0% and for plants with visible buds 31.4%.     

秋水仙素诱导甜高粱‘FH59’种子变异效应研究

为了研究秋水仙素水溶液对甜高粱‘FH59’种子的诱变效应,创制优质甜高粱种质资源。本实验利用不同浓度的秋水仙素水溶液(0.05%、0.1%、0.15%、0.2%)浸泡甜高粱种子24、31、48 h,统计苗期变异率,并对成活植株进行大田鉴定。研究结果表明,秋水仙素诱变效果受到处理时间、药剂浓度以及二者交互作用的显著影响,在24 h,0.15%诱变条件下诱变效果最佳,幼苗变异效果显著。M₂代田间鉴定发现株高、生育期、穗长、籽粒颜色、锤度等主要农艺性状的突变体,变异类型丰富,尤其是发现的大量的矮化、早熟突变体对甜高粱亲本的改良作用明显。     

小麦与玉米杂交产生小麦单倍体与双单倍体的稳定性

小麦与玉米杂交是诱导小麦单倍体最有效的途径之一, 但单倍体和双单倍体产生频率不稳定影响了该技术的应用。选用13个小麦杂种F₁代单交组合与玉米杂交, 研究了不同小麦生长环境、生长素处理、培养基和壮苗处理对单倍体及双单倍体产生频率的影响。小麦生长在大田, 去雄后割穗培养与玉米杂交平均得胚率为23.9%, 每个杂交穗平均得胚数6.8个, 均是返青后从大田移回冷温室盆栽的3倍以上;不同小麦杂交组合间胚产生频率存在明显差异。生长素Dicamba蘸穗处理平均得胚率是21.5%, 与2,4-D处理得胚率(21.1%)无显著差异, 但不同杂交组合间差异显著。B5培养基幼胚萌发率为70.9%~88.3%, 平均82.0%;1/2 MS培养基胚萌发率为70.0%~86.0%, 平均76.6%;两种培养基平均胚萌发率无显著差异。试管苗经壮苗培养基壮苗处理与试管苗经移栽壮苗处理后加倍效率分别是67.6%和8.6%。移栽壮苗处理的苗分蘖少, 生长较弱, 加倍处理后存活率低和加倍率低是其单倍体加倍效率低的原因。     

Effect of chromosome-doubling agents on somaclonal variation in the progeny of doubled haploids of maize

This study was carried out to determine whether the treatment of anther-culture-derived haploid callus of maize (Zea mays) with chromosome-doubling agents, such as colchicine or the herbicides pronamide and amiprophos-methyl (APM), induces higher than normal levels of somaclonal variation. A total of 79 R₁ families produced by diploid regenerated plants resulting from chromosome-doubling treatments were evaluated in the field in comparison with the three parental inbreds. Four qualitative variant phenotypes — male sterility, chlorophyll deficiency, earless plants, and short plants with narrow leaves and thin stalks —– were observed. The last phenotype (narrow leaves and thin stalks) was also found in the inbreds FR16 and H99 grown from seed, so it may not be directly related to the tissue-culture conditions or the anti-microtubule-agent treatments. The frequency of R₁ families segregating for the other three mutations was 3.8%, which is no higher than the somaclonal variation frequencies observed previously in tissue-culture-derived maize plants. Observations of three quantitative traits—–days to anthesis, days to silk emergence, and plant height—– also failed to detect any extra variation that could be related to the treatments with anti-microtubule agents. These studies indicate that the anti-microtubule agents APM, pronamide and colchicine can be used to induce chromosome doubling of anther-culture-derived callus to produce a high proportion of doubled haploid plants without causing increased rates of mutation (somaclonal variation).     

亏缺灌溉西瓜营养生长期适宜滴灌频率研究

为了探求膜下亏缺灌溉条件下大棚西瓜营养生长期的最佳滴灌频率,为西北干旱半干旱地区设施西瓜合理灌溉提供理论指导,笔者以‘农科大11 号’西瓜为试材,以室内蒸发皿水面蒸发量的0.4 倍为亏缺灌水量,试验共设置T1、T2、T3 共3 个灌水频率处理,分别为每2 天灌1 次水（高频）、每4 天灌1 次水（中频）和每6 天灌1 次水（低频）,研究了滴灌频率对西瓜营养生长期根区土壤含水量、植株生长以及相关生理指标的影响。试验结果表明：T2 下根区0~20 cm土层的土壤水分条件最适宜营养生长期的生长,植株叶绿素含量、净光合速率和叶片水分利用效率达到最高,光合同化能力强,且西瓜叶片能够保持适宜的细胞汁液浓度和细胞水分代谢水平。整体而言,T2 西瓜营养生长期长势较好,植株健壮,抗逆性更强,有利于抵抗早春大棚各种逆境胁迫。综合考虑土壤水分分布、生理及生长指标,T2 即每4 天灌1 次水是西北地区早春大棚西瓜营养生长期亏缺灌溉条件下最佳灌溉频率。该研究可为提高西瓜营养生长期亏缺灌溉水分利用效率提供参考依据。     

秋水仙素对辣椒生长的影响及多倍体诱导效应研究

以秋水仙素为诱变剂,比较了不同浓度和不同处理时长组合下辣椒(Capsicum annuum L.)的生长差异和多倍体诱导效应.结果表明:和对照植株相比,所有处理变异植株在形态上表现为叶片宽大,叶色较深,茎变粗且节间距长,气孔增大;相关指标都表现出显著或极显著的差异,而且随着处理强度的增加差异更为明显.秋水仙素诱导产生的变异植株经染色体倍性鉴定植株表征为嵌合体(2 n=24或2 n=48).相同处理时长下,不同浓度秋水仙素溶液对辣椒多倍体诱导效应差异显著,而对相同浓度下不同处理时长对植株叶片数和气孔面积影响差异不显著(P>0.05),其它指标差异极显著(P<0.01).秋水仙素浓度与处理时长之间存在交互作用,不同处理之间除气孔面积差异不显著之外,其它指标间差异显著或极显著.结合加倍率和植株死亡率综合分析后认为,用0.05%的秋水仙素溶液处理6天诱导效果最佳,诱导诱导加倍率可达26.1%.