4x-2x杂交创制马铃薯新种质

以二倍体马铃薯‘USW4’和Solanum chacoense杂交产生的F1株系‘XD-3’为材料,检测其2n花粉产率和花粉活力。研究结果表明,‘XD-3’能产生2n花粉,2n花粉产率约7.7%,且花粉活力较高,达74.75%。在此基础上,开展了4x-2x杂交,进行了4个不同的杂交组合,平均杂交结实率为36.5%,但平均种子数/浆果仅0.67粒。4个不同的杂交组合共获得19个杂交后代,2对父本特异的SSR引物检测结果表明,有14个株系可以确认为真杂种;杂种植株的倍性检测结果表明,7个为三倍体,7个为四倍体。大量三倍体的产生为n花粉的直接利用提供了一条新思路。     

马铃薯二倍体栽培种S.phureja与普通栽培种的四倍体杂种品质性状育种价值的研究

试验选用 3份含有二倍体栽培种富利亚薯 (Solanum phureja)血缘的 4x 2x四倍体杂种材料和 1份四倍体普通栽培种 (Solanumtuberosum )优良无性系为亲本 ,按照Griffing方法Ⅲ配制成双列杂交组合 12个 (包括正交 6个 ,反交 6个 ) ,分析了杂种实生苗当代薯形、品质等 6个性状的群体遗传参数和配合力效应。遗传分析结果表明 ,芽眼深度、比重、Vc含量、还原糖含量等 6个被测性状的遗传变异均以加性效应为主。配合力效应估算结果表明 ,同一性状的一般配合力效应值在不同亲本间差异亦较大 ,并且同一性状的特殊配合力效应值在不同组合间差异亦较大。本试验结果还表明 ,比重上存在极显著的反交效应     

对马铃薯4x-2x,2x-4x及2x-2x杂种四倍体进行花药培养获得转育2n配子基因的双单倍体新个体

利用3个2n配子材料(2x)在马铃薯(S.tuberosum L.)中进行4x—2x,2x—4x和2x—2x的杂交,获得了4个四倍体杂种材料;然后对它们进行花药培养,共得到32个双单倍体植株。检查其中23个植株,有2株是具5％以上2n花粉粒的双单倍体,1株是重组了2n卵基因的双单倍体。由此证明花药培养的倍性操作技术是转育马铃薯2n配子性状给双单倍体的有效方法之一。     

同源四倍体水稻与非洲栽培稻杂交的后效性研究

利用亚洲栽培稻中的4份同源四倍体水稻(O.sativa,2n=4x=48)和相应的4份二倍体水稻(O.sativa,2n=2x=24)为母本,以4份非洲栽培稻(O.glaberrima,2n=2x=24)为花粉供体进行远缘杂交后,对其杂种后代的分离动态进行了研究.结果表明,不同倍性的普通栽培稻与非洲栽培稻之间杂交后代的结实率以二倍体普通栽培稻的较高.在配制的32个杂交组合中,其杂种第1代群体均表现出明显的营养生长优势.从群体的生长势来看,杂种第2代群体比杂种第1代群体要弱一些;在杂种第2代群体中,以同源四倍体水稻为母本的杂交组合的分离现象比以二倍体水稻为母本的杂交组合的分离现象更明显.在各杂交组合的第3代群体中,从植株的株叶形态和生育期来看,株系间的差异和株系内的变异依然很明显,变异频率更宽,变异种类更多.在普通栽培稻与非洲栽培稻的杂交组合中,育性变异、生长势变异、株叶形态变异、染色体变异和结实性变异等是较易发现的变异现象.     

马铃薯杂交组合选配与亲本性状遗传关系的研究

<正> 1 前言掌握亲本特征特性、配制最优杂交组合并于实生苗世代进行有效选择,是马铃薯育种工作的关键.本试验采用的杂交亲本在熟期方面有早熟、中熟和中晚熟3种;在品种和品系方面,包括有普通栽培种和新型栽培种,因此,使杂种后代能在广泛的遗传基础上进行重组.弄清亲本与后代间主要性状遗传相关性,可提高实生苗及以后各无性世代的选择效果.     

在研究马铃薯对病原菌抗病能级育种工作中利用双单体和未减数配子的评价

在马铃薯抗晚疫病(Phytophora infestans)和抗乳状马铃薯胞囊线虫病(Globodera pollida)育种程序中,从双单体(2n=24)为亲本的杂交后代中获得的四倍体(4x)植株,大体上雌蕊是四倍体。在温室和田间对第一年和第二年块茎的测定表明,大多数高抗疫病的双单倍体的后代也表现高抗马铃薯晚疫病。用双单体PDH182和PDH247分别与一个四倍体杂交,选择一般配合力高且高抗马铃薯胞囊线虫病(PCN)的个体,其后代高抗晚疫病,且有1/3的植株也高抗PCN。对双单倍体×4x的杂交组合后代,在实生苗世代进行离体片鉴定,来快速筛选疫病抗性。观察来自不同抗疲病双单倍体后代的平均抗性,发现四倍体亲本之间是有差异的。试验同时证明,不同的双单倍体在疫病的抗性程度上,对后代的遗传传递力是有差异的。这可归因于未减数配子组成方式的差异,即减数分裂时第一次分裂的重组或第二次分裂的重组(SDR)都有差异。如果所有未减数配子都由SDR产生,则这种差异可归因于不同双单倍体之间抗疫病基因纯合程度上的差异。这种双单体×4x的杂交组合,每个授粉株只产生很少的后代。这少量的实生苗可能以比较高的频率产生带有目标性状的后代。由于必须种植这少量的实生苗,以便找到所要求的重组性状,所以在种植中寻求补救措施,而抗性鉴定要比常规育种方便得多。所得到的这些四倍体杂种可以同时在三个方面用于第二轮的育种工作:即,与其它的四倍体杂交;与双单倍体杂交以选择互补性状,以及产生综合多种抗性的双单倍体。     

马铃薯杂种后代无性系性状的评价

西藏马铃薯种质资源丰富,但主栽品种较少,专用品种匮乏。利用西藏当地马铃薯品种做亲本配置组合,进行马铃薯杂种后代无性系性状评价,为选育适合西藏当地生态环境的马铃薯专用品种提供参考。被测无性系17个,以当地品种‘艾玛土豆’和油炸品种‘大西洋’为对照,进行植株性状、产量性状、品质性状及炸条级别的评价。试验结果表明,‘XZ07-1’产量与商品薯重均达最高,适合鲜薯食用;‘XZ25-1’淀粉含量最高18.59%,薯肉为白色,适合淀粉加工;‘XZ14-1’产量与商品薯率高,还原糖含量低于对照‘大西洋’,炸条级别为1级,适合油炸或全粉加工。另有9个无性系部分性状表现较好,可进一步评价,并对其优良特性在育种中加以利用。因此,利用西藏当地马铃薯品种资源可选育适合西藏当地生态环境的马铃薯专用新品种。     

快速测定活体马铃薯花柱上2X和X花粉间的竞争

由栽培马铃薯(4x)(S.tuberosum)与富利亚薯(2x)(S.phureja)杂交获得马铃薯双单倍体。依所采用的花粉不同,这些杂交所产生的后代包括不同数目的母体双单倍体、三倍体和四倍体杂种。由于存在胚株致死现象,仅有少量三倍体产生。由2x 花粉衍生得四倍体杂种,其频率比在以不同花粉授粉的条件下,从2x 花粉获得的期望频率要高些。H(?)glund(1970)提出两个假说来解释出现大量四倍体的问题,或是2x     

马铃薯种间体细胞杂种植株的细胞学观察和过氧化物同工酶谱分析

对马铃薯双单倍体品系81－15（2n＝2x－24）和南美二倍体栽培种Solanumphureja（2n＝2x＝24）体细胞融合获得的15个林系、81－15和二倍体野生种S．chacoense（2n＝2x＝24）体细胞融合获得的10个株系进行了细胞学鉴定和过氧化物同工酶谱分析。结果表明,杂种植株除一个株系为非整倍体外（染色体数为37）,其余株系均为四倍体（2n＝2x＝48）,是两个亲本的染色体数之和。与二倍体的双亲相比,杂种植株的叶下表皮气孔保卫细胞内叶绿体数目较多,但单位面积气孔数目较少,明显地表现出了四倍体的特征。杂种植株的过氧化物同工酶谱是其双亲酶谱谱带的总和。     

利用体细胞杂交获取马铃薯软腐病的抗性

对马铃薯四倍体栽培种和二倍体野生种Solanumbrevidens的体细胞杂种通过叶片离体培养获得的四倍体植株,以及用四倍体栽培种进行回交获得的五倍体植株的块茎对软腐病的抗性进行了测定。结果表明,由体细胞杂种通过叶片组织离体培养再生植株中,有一个株系SC107对软腐病菌Erwiniacarotovora具有较强的抗性。在用不抗软腐病的马铃薯栽培种对体细胞杂种进行回交获得的杂种后代中,大部分株系对软腐病菌具有高水平的抗性,从而说明Solanumbrevidens对软腐病的抗性基因已转移到马铃薯栽培种。     

Yield potential and genotype-environment interactions of tetraploid-diploid (4x-2x) potato hybrids

Six advanced selections of a population of 4x-2x hybrids were tested and compared with six well-adapted Group Tuberosum cultivars under field conditions at four locations in Canada over two years. Three 4x-2x hybrids produced a total and a marketable yield which was equal to or higher than that of most cultivars over eight environments. For marketable yield considerable differences existed between genotypes in the amount of variation occurring over the eight environments. Both groups of genotypes contained clones with low and high variation for marketable yield. Analysis of genotype-environment (GE) interactions for marketable yield indicated that all genotypes differed from each other in their responses to the environmental effects. However, there was no clear distinction between the group of 4x-2x hybrids and the group of cultivars for the GE interaction patterns. It appears that the heterosis of the 4x-2x hybrids is the result of a broadening of the genetic base of Group Tuberosum breeding stocks by the incorporation of germ plasm from the primitive diploid South American cultivars. Development of improved diploid parents is necessary in order to achieve the full potential of the 4x-2x hybridization method.     

马铃薯倍性育种优良育成材料鉴定评价

通过连续多年对马铃薯的倍性育种研究,已创造出10份2n配子频率30%以上,花粉育性强,抗青枯病、病毒病及晚疫病,产量高,块茎性状较好的2n配子材料。将其与一批优良的4x普通栽培种杂交,获得了982n10-8等7份各种性状均超过对照的优良品系,从目前的试验结果来看,具有很强的杂种优势。     

Breeding value of 2n pollen diploid from hybrids and Phureja in 4x-2x crosses in potatoes

Breeding value of 2n pollen from Phureja — haploid Group Tuberosum diploid hybrids (DHs) and Phureja was compared in crosses with tetraploid cultivars. Mean total yield for Phureja — derived (PT) hybrids significantly exceeded that for DH — derived (DHT) hybrids, and did not differ from that for cultivar parents. PT hybrids had the largest range for total yield, with 13% of the population between 4200 and 5750 gm/plant (0.8 and 4.6% for DHT hybrids and cultivars, respectively). Moreover, the tail of the frequency distribution of total yield for PT hybrids extended 920 gm/plant above that for cultivars. Mean marketable yield for PT hybrids significantly exceeded that for DHT hybrids, but was significantly below that for cultivars. However, the tail of the distribution of marketable yields for PT hybrids exceeded that of the cultivars by 820 gm/plant. Significant general combining ability among 2x and 4x parents for total and marketable yield indicates that the potential of specific crosses can be predicted by average performance of parents in test-crosses. Predictability of parental breeding value and exceptional yield potential of hybrids make 4x-2x breeding an attractive alternative to conventional approaches.     

Resistance to soft rot (Erwinia carotovora subsp.atroseptica) in tetraploid potato families obtained from 4x-2x crosses

Diploid potato clones, interspecific hybrids ofSolanum species, having in their originS. tuberosum,S. chacoense, S. yungasense, S. phureja, S. gourlayi, andS. demissum, with resistance to soft rot, were crossed to tetraploid potato clones in 4x-2x crosses. The 24 tetraploid families obtained in a North Carolina II design were examined for tuber resistance to soft rot in a laboratory test and for basic agronomic traits in field trials conducted for two consecutive years. In addition, one family originating from a 4x-2x cross of two susceptible parents was tested. Statistical analysis of the data revealed significant general (GCA) and specific combining ability (SCA) effects, year, GCA (female) × year, GCA (male) × year, and SCA × year upon the inheritance of resistance to soft rot. About 35% of the progeny was selected as resistant to tuber soft rot, and of these 11% showed high resistance combined with good tuber yield, tuber weight, and tuber appearance. The relationships between resistance to soft rot and chosen agronomic traits were not noted or were weakly significant and sporadic. The resistance to tuber soft rot found in diploid potato hybrids can be transferred to the cultivated tetraploid pool through 4x-2x crosses, and a high frequency of offspring posses resistance.     

Male sterility and 2n pollen in 4x progenies derived from 4x×2x and 4x×4x crosses in potatoes

Summary The objectives of these experiments were to evaluate male sterility (MS) and 2n pollen frequency in 77 4x×2x families and 26 4x×4x families. The 2x parents were haploid-species hybrids and the 4x parents mainly clones withS. tuberosum ssp.tuberosum (tbr) andS. tuberosum ssp.andigena (adg) in their genetic background. The female parents had different cytoplasms: adg, tbr,S. demissum (dms), andS. stoloniferum (sto). Families from female parents with adg or dms cytoplasm did not have MS plants. However, families derived from crosses of many tbr females with 2x hybrids and a 4x adg clone had a high percentage of MS plants; all the progenies from cv. Serrana (sto cytoplasm) possessed tetrad sterility. These results can be explained as due to an interaction between a dominant male sterility (Ms) gene with tbr and sto cytoplasms. Some MS 4x hybrids (tbr×adg) used as females had the Ms gene, but male fertility was restored in some plants of their progenies when they were crossed with 4x tbr clones. This indicates that some tbr clones have a fertility restorer gene (Rt). The results from both 4x×2x and 4x×4x families fit the expected ratios assuming chromatid segregation for both the Ms and Rt loci. The gene frequency of parallel spindles was estimated in the 4x population as 0.74.     

Performance and stability of nine 4x clones from 4x−2x crosses and four commercial cultivars

Summary Nine clones from 4x−2x crosses were evaluated along with four cultivars in six Wisconsin environments. The 4x clones from 4x−2x crosses had as their 2x parents hybrids with haploid Tuberosum and either Group Phureja orSolanum tarijense. The 2x hybrids produced 2n pollen by first division restitution. The traits evaluated were marketable yield, mass density and chip color. Stability analysis was conducted by determining the linear relationships between mean yield of individual clones and environmental mean yields. Mean square deviations from linear regression (s² _d) were used to evaluate phenotypic stability and regression coefficients (b) as environmental response parameters. Three 4x clones from 4x-2x crosses were more stable and not significantly different for yield than cv. Atlantic; some also had superior specific gravity and chip color. The results suggest that the 4x×2x breeding method is very efficient for the production of high yielding, stable clones with superior processing qualities, particularly since the 4x clones from 4x-2x crosses originated from very small source populations.     

The effect of direction of hybridization (4x × 2x vs. 2x × 4x) on yield of cultivated potatoes

The types of reciprocal differences found in higher plants are generally limited to those characters which are controlled by one or two major genes. There are, however, a few examples where the progeny from reciprocal crosses differ in yield or other quantitative characters. Both have been ascribed mainly to cytoplasmic inheritance. In cultivated tetraploid potatoes (Solatium tuberosum Group Tuberosum) differences in yield of the progeny from reciprocal crosses have been found. These reciprocal differences are attributed to the mode of 2n gamete formation rather than cytoplasmic differences. Preliminary experiments involving reciprocal crosses between Tuberosum cultivars (2n=4x=48) and Phurejahaploid Tuberosum hybrids (2n=2x=24) indicated that some progenies from 4x x 2x crosses yield more than progenies from reciprocal crosses. It was hypothesized that the differences in tuber yield may be due to one or more of the following factors: (i) the effect of high fruit set on yield —i.e. almost 100% of the progenies from 2x X 4x crosses are male fertile and thus higher fruit set is expected than in the 4x X 2x progenies where only about 57% of the F₁ clones are male fertile; (ii) the advantage of being in 4x cytoplasm if the nucleus is 4x; and (iii) the difference in mode of 2n gamete formation-first division restitution (FDR) gives highly heterozygous gametes and second division restitution (SDR) results in highly homozygous gametes. Six families of reciprocal crosses between three 4x cultivars (Merrimack, Superior, and Wis 639) and three 2x Phureja-haploid clones (W5293.3, W5295.7, and W5845.1) were planted in 1970 in Rhinelander in a split-plot design with two tubers of each clone in each of two replicates. Flowers were removed from one of the paired plants in each family. Even though the fruit yields were higher in 2x X 4x progenies as expected, tuber yields were not affected by fruit formation. Therefore, factor (i) is apparently not involved in the reciprocal differences observed. Significantly higher tuber yields were obtained from 4x X 2x families only with the 2x clone W5295.7. This eliminated factor (ii), since no difference in reciprocals was obtained with the other 2x clones. Factor (iii) could thus be responsible for differences in reciprocal crosses, since cytological observations indicate only W5295.7 of the 2x clones used forms 2n pollen by FDR.     

Yield and tuber characteristics of 4x progeny from 2x×2x crosses

Summary Unrelated, unselected 2x haploid-species hybrids that produce 2n eggs, by second division restitution and 2n pollen due to first division restitution were intercrossed to generate 4x progeny. The 19, 4x families were compared with seven cultivars for tuber yield, tuber appearance and tuber set. The mean yield of the 4x families was 30% higher than the mean yield of the cultivars. The best five 4x families outyielded the best five cultivars by 57% and 69% at two locations. Cultivars were superior for tuber appearance and tuber set. The high yields of the 4x families are due to genetic diversity of the 2x parents and their ability to transmit that diversity to the 4x progeny utilizing 2n gametes. The potential of the 2x×2x breeding method is dependent on developing 2x hybrid clones that form 2n eggs and possess desirable tuber types; clones producing 2n pollen and good tuber quality are available.