双单倍体(DH)技术可使杂合育种材料在一个世代纯合稳定,被广泛用于作物遗传育种.小麦×玉米杂交是产生小麦DH的主要途径之一,但小麦和玉米一般在不同季节种植,制约了该技术的广泛应用.春性和经春化处理的半冬性、冬性小麦材料在云南昆明 自然条件下一年四季均可播种、收获,为每年4月至12月进行小麦×玉米杂交提供了便利条件.本团队前期建立了平均得胚率为25％(15％～70％)、成苗率为62％(50％～80％)以及加倍率为62％(50％～90％)的小麦DH批量生产技术规程.并于2015年以来,利用国内外共1 900余份不同遗传背景的春性、半冬性和冬性小麦材料进行验证,共获得10.5×104个小麦DH株系;构建了 64个DH遗传群体;育成了云麦110、云麦112等小麦新品种;创制了 24个优良小麦温光敏核不育系及一批抗病优良品系,初步实现了该DH技术在小麦育种中的应用.后续还需继续完善规模化DH生产技术规程,提高得胚率、成苗率、加倍率等关键技术指标和DH生产效率,降低成本,促进该技术在小麦遗传育种中更广泛地应用.

Wheat is one of the most important food crops in Yunnan Province. Drought and yellow rust are the main limiting factors to wheat productivity. Utilization of heterosis is expected to be a promising way to increase resistance to stress and yield potential. In 1992, photo-thermo sensitive genic male sterile wheat "ES" and thermo-photo sensitive genic male sterile wheat "C49S" were developed by Hunan Agricultural University and Chongqing Academy of Agricultural Science, respectively, which provided a new way for heterosis utilization in China by conducting two-line hybrid wheat breeding. ES and C49S were sterile under low-temperature and short-day conditions, and fertile under high-temperature and long-day conditions. During 1993-2000, ten sterile lines of ES and C49S were introduced into Yunnan for sterility identification, while only C49S-87 from Chongqing showed stable sterility in three special locations of Yunnan when sowed in middle October, with 15-20 d of sterile heading duration (bagged seed-set rate <1%). In 2002, hybrid cultivar Yunza 3 from C49S-87 was released in Yunnan and increased yield by 11.4% over the inbred CK in regional tests, but was planted only 12400 ha in Yunnan due to the loss of resistance to yellow rust after 2004. Given that C49S-87 was poor in out-crossing ability (40%-50%) and susceptible to yellow rust, an improved sterile line K78S was developed from C49S-87 in 2001. K78S had 26-44 d of sterile heading duration in all regions with altitudes from 1530 to 2400 m when sowed from middle October to early November, as well as better out-crossing ability (70%-80%) and higher resistance to yellow rust. In 2004 and 2005, Yunza 5 and Yunza 6 developed from K78S were separately released in Yunnan. Both cultivars showed higher yield increase by >15% in regional tests. Meanwhile, high cross-pollination ability of K78S markedly raised the yield of hybrid seed production from 1500-1800 kg/ha of Yunza 3 to 3900-4500 kg/ha of Yunza 5 and Yunza 6 when the same techniques of mechanized seed production were applied. These cultivars have been totally planted about 700000 ha in Yunnan and parts of Vietnam till now. However, since 2005, no hybrid cultivar has been released in Yunnan. The main reasons are as follows: (1) Only two sterile lines were practically used for test-crossing before 2020 but became susceptible to yellow rust ten years ago, which greatly reduced the opportunities of creating high heterotic hybrids although thousands of restorers were test-crossed. In 2020, 24 elite sterile lines were developed by using doubled haploid (DH) breeding, and have been used in hybrid wheat breeding now. (2) Most restorers were "by-products" of developing inbred cultivars, thus the combining ability between the sterile line and the restorer was never tested during the developing of restorers, resulting in completely random or accidental emergence of heterotic hybrids. Therefore, it might be necessary to re-construct the restorer breeding program by using dwarf-male-sterile wheat with reference to maize inbred line breeding. In addition, exploitation of nucleo-cytoplasmic heterosis might be another way to increase heterosis both in yield potential and resistance to stress, as suggested by Kihara in 1979. Generally, some promising progress in two-line hybrid wheat breeding based on thermo-photo sensitive genic male sterility has been achieved in Yunnan during past 30 years. However, more efforts should be made in breeding and basic research to efficiently create hybrids with higher yield increase and better resistance to drought and diseases, and this will improve the current system and promote the wider application of hybrid wheat in Yunnan.

云麦112是云南省农业科学院粮食作物研究所采用太谷核不育群体改良获得的优异单株再通过小麦×玉米产生双单倍体技术快速纯化产生的稳定品系选育而成.该品种属弱春性,幼苗半匍匐,分蘖成穗好;株高82.2cm,株型松紧适中,生育期适中;籽粒饱满,熟相好,易落粒,属中筋小麦.产量三要素协调,高抗条锈病和白粉病,抗叶锈病,耐寒、耐旱、抗倒伏.云麦112是一个多抗旱地小麦新品种,适宜在云南省海拔1260～1900m地麦生产区种植.

Background: Two-line hybrid wheat system using thermo-photo sensitive genic male sterility (TPSGMS) is currently the most promising approach for wheat heterosis utilization in China. However, during past twenty years only few TPSGMS lines were developed in hybrid wheat breeding, which has been the main limiting factor to create heterotic hybrids. Application of doubled haploid (DH) breeding provides a useful strategy to efficiently develop practically usable TPSGMS lines. Results: F 1 s and selected F 2 and F 3 sterile plants of eight crosses made from two commercial TPSGMS lines were used to produce DH lines. We developed a total of 24 elite DH sterile lines with stable sterility, good outcrossing and yield potential, resistance to yellow rust and powdery mildew, as well as desirable plant height (50-60 cm). These DH lines were developed within 4 years through at least one year of evaluation. The stability of male sterility was confirmed for most (20/24) of these elite DH sterile lines by multiple tests in two or three years. These lines are expected to be used in hybrid wheat breeding. The percentage of elite lines developed from the tested DH lines produced from filial generations was in the order of F 2 > F 3 > F 1 . Conclusions: We demonstrate that coupling DH techniques with conventional breeding is an efficient strategy for accelerating the development of more practical wheat TPSGMS lines. Generation of DHs from F 2 generation appeared to be the better choice considering the balance of shortening breeding time and overall breeding efficiency.

S IX selected bread wheat double haploid genotypes with same heading time and different genetic background and eight maize genotypes belonging to four maize types (waxy, sweet waxy, sweet and super sweet maize types) were used in this study.The six wheat genotypes pollinated with the eight maize genotypes to produce wheat haploid embryos.The objective of this investigation was to study the effects of different maize genotypes of distinct types on the wheat haploid embryo ratio.The results showed that the same wheat material when pollinated with different maize genotype, the embryo rate differed between 1.5 to 3 times and ranging from 15.43% to 47.80%.Screening high induction rate maize varieties was essential to improve the efficiency of wheat haploid production.The average haploid embryo induction rate among the four maize types was highest in sweet type (33.24%) and lowest in super sweet type (29.59%).The wheat genotype A6 recorded the highest embryo rate percentage (34.11%),while A5 recorded the lowest rate (29.36%).Baitiannuo SQW-1 (B4) found to be the highest for embryo rate, followed by the Yuntianyu 6 (B5) and Zhenhenuo 1(B1), while the lowest was recorded by Yunchaotian 2 (B8) genotype.The maize genotypes in the same type differed significantly regarding the haploid embryo induction rate of wheat genotypes and thus maize types were not consistent in their behavior.So, the key was to select maize genotypes with high induction rate for wheat haploids and not the maize type.The interaction between wheat genotype and maize genotype has a significant effect on the embryogenesis rate.Therefore, if the rate of embryo induction of some wheat materials with a common maize variety is low, it may be possible using the pollination of other maize genotypes to increase the embryogenesis in wheat x maize hybridization.

为筛选小麦单倍体胚得胚率高的玉米品种,用糯、甜糯、甜、超甜4种类型共8个玉米品种分别与6个小麦DH系杂交诱导产生小麦单倍体胚,研究不同玉米类型、不同玉米基因型对小麦单倍体胚得胚率的影响.结果表明,同一小麦材料用不同玉米品种授粉,其得胚率可相差1.48～3.10倍,得胚率变幅为15.43％～47.80％,筛选高得胚率玉米品种对提高小麦单倍体产生效率至关重要.4种玉米类型间平均单倍体胚得胚率以甜糯型最高(33.86％)、超甜型最低(29.59％),8个玉米品种以白甜糯的平均单倍体胚得胚率最高(38.17％),云超甜2号最低(28.63％),但相同玉米类型而基因型不同的玉米品种间单倍体胚得胚率差异大于玉米类型间单倍体胚得胚率的差异,因此筛选高得胚率玉米品种,关键是筛选玉米基因型而非玉米类型.小麦基因型与玉米基因型的互作对得胚率有极显著影响,对于小麦×玉米杂交的得胚率,玉米基因型与小麦基因型之间的组合存在"一般配合力"和"特殊配合力"的差异,因此可综合利用多个玉米品种来提高各种小麦材料的整体单倍体胚得胚率和单倍体生产效率.

This study was conducted to identify desirable wheat germplasm for superior hybrid cross combinations through 1) identifying the best parents with high combining ability (CA) and 2) estimating heterosis effects. Two thermophoto-sensitive-genic-male-sterile lines (K456s and K78s) as female parents and 60 restorer lines as males were crossed according to line × tester hybridization method. The observed variation for most of the nine studied characters and <1 ratio for general (G)/specific (S) CA suggested governance of non-additive gene action. The GCA for K456s was higher than K78s in six out of nine characters, while restorers 2016Y2-2776 and 2016Y2- 4117 had the highest in five characters. The crosses K78s/R31 and K456s/R2 had highest positive SCA values in five and six characters, respectively. The crosses K78s/R43 and K456s/R21 had the overall highest significant positive heterosis estimates for the best cross with respect to yield plant-1and has the potential for utilization in hybrid wheat breeding program.

Background: Two-line hybrid wheat system using thermo-photo sensitive genic male sterility (TPSGMS) is now a dominant and promising approach of wheat heterosis utilization in China. However, during past twenty years only several TPSGMS lines have been capable of practical application in hybrid wheat breeding and production, which reduced the opportunities and efficiency of creating hybrids with strong heterosis. Introducing doubled haploid (DH) breeding could be a helpful strategy to efficiently develop practically usable TPSGMS lines. Results: F 1 s and selected F 2 and F 3 sterile plants from eight crosses made from two commercial TPSGMS lines were used to produce DH lines by using the wheat × maize system. Twenty four elite sterile lines possessing stable sterility, good outcrossing and yield potential, resistance to yellow rust and powdery mildew, and desirable plant height (50-60 cm) were obtained within 4 years through at least one year evaluation. Twenty from twenty four elite lines showed stable sterility in repeated tests of two or three years, will be selected for hybrid breeding. The percentage of elite lines within total tested DH lines produced from filial generations was in the order of F 2 > F 3 > F 1 in this study. Conclusions: Our study shows that DH breeding is more efficient for the selection of traits controlled by recessive gene(s) compared with conventional breeding, especially for the sterility of TPSGMS wheat. Coupling DH techniques with conventional breeding would be an efficient strategy for developing practically usable wheat TPSGMS lines in respect to number and saving time, which is helpful for further improving the efficiency of wheat hybrid breeding. Producing DHs from F 2 generation appeared to be the better choice considering the balance of shortening breeding time and overall breeding efficiency.

[Objective]The objective of the present paper is to provide reference for introducing resources of durum wheat into common wheat to breed new wheat varieties.[Method] 13 agronomic traits of 12 new wheat lines,which were from distant hybridization between durum wheat and common wheat by the technique of producing doubled haploid of wheat by wide hybridization between wheat and maize,were generally described and quantitatively evaluated by the grey relational analysis method.[Result] The order of comprehensive evaluation score of 12 new wheat lines from high to low was 14Y2-919,14Y2-873,14Y2-939,14Y2-838,14Y2-931,14Y2-1052,14Y2-874,14Y2-918,14Y2-988,14Y2-987,14Y2-834 and 14Y2-973.Weighted correlation degree of the grey relational analysis method could reflect the actual performance of wheat cultivars more accurately,thus it was an effective method for comprehensive evaluation of new wheat lines.[Conclusion] Based on comprehensive evaluation,it was found that 14Y2-919 was the best,followed by 14Y2-873,14Y2-939 and 14Y2-838.These new lines can be used for further breeding new wheat varieties for the Yunnan-Guizhou plateau wheat region.

[目的]为了明确硬粒小麦资源在云南高原麦区对普通小麦改良效果.[方法]以12个通过硬粒小麦×普通小麦远缘杂交获得的小麦稳定品系和19个通过普通小麦×普通小麦种内杂交获得的小麦稳定品系为试验材料,采用t测验法对2种途径获得的小麦稳定品系的产量性状与品质性状差异进行了研究.[结果]通过硬粒小麦与普通小麦远缘杂交选育的小麦新品系小区产量和有效穗高于通过普通小麦与普通小麦种内杂交选育的小麦新品系,小区产量差异极显著(t=3.311**),有效穗差异极显著(t=2.157*);硬粒小麦与普通小麦远缘杂交选育的小麦新品系的千粒重和穗粒数低于普通小麦与普通小麦种内杂交选育的小麦新品系,但是千粒重和穗粒数差异均不显著;通过硬粒小麦与普通小麦远缘杂交选育的小麦品系在标准吸水率、容重、稳定时间和硬度值高于通过普通小麦与普通小麦种内杂交选育的小麦新品系,而蛋白含量、湿面筋含量、形成时间、沉降值和出粉率却低于通过普通小麦与普通小麦种内杂交选育的小麦新品系,但9个品质性状差异不显著.[结论]在云南高原麦区,硬粒小麦资源在普通小麦改良中可以通过改进普通小麦有效穗进而提高产量,然而对普通小麦品质性状的改良效果却不显著.

[Objective] This study was conducted to understand the relationship between yield-related traits and yield of Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety,and make contribution of yield-related traits to the yield of Yunmai 52 clear.[Method] Wheat variety regional trial data in Yunnan Province in 2005-2007 were subjected to correlation analysis and path analysis in the paper.[Result] Correlationanalysis showed that the yield of Yunmai 52 was invery significant positive correlation with spikelet number per ear,maximum tiller number and grains per ear (r=0.726**,0.717** and 0.695**,respectively),in significant positive correlation with 1 000-grain weight (r=0.491*),but in significant negative correlation with sterile spikelet number per ear,and in non-significant correlation with basic seedlings,effective ears and percentage of ear bearing tillers.Partial correlation analysis showed that the yield of Yunmai 52 was in very significant positive correlation with spikelet number per ear (r=0.711 **),significant positive correlation with 1 000-grain weight (r=0.641*),but in non-significant correlation with other 6 traits.Path analysis showed that spikelet number per ear (P=0.595),maximum tiller number (P=0.462) and 1 000-grain weight (P=0.263) had more contribution to yield of Yunmai 52.[Conclusion] Therefore,in extension and application of Yunmai 52that is a high-quality high-yield multi-resistant new wheat variety,supply of fertilizer and water should be increased in tillering stage and jointing stage,to ensure its characteristics of high tillering ability and large ear,as well as high 1 000-grain weight,and coordinated development of other yield-related traits is beneficial to improvement of yield of Yunmai 52.

The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter inducing period, easy operation, and so on. At present, it is the most efficient and has great potential of application in breeding of wheat. This article reviewed principle and production process of the technique, research situation of the three key indicators of the technology(embryo rate, seedling rate and success rate of doubling)in recent years, and application of the technology in breeding, genetics, germplasm improvement of wheat. At last, both the achievements and the direction of further improvement and development of the technology in our program were discussed.

云麦52系1992年用6AL/6VS易位系92R149作抗病亲本,2007年审定并推广应用的小麦品种,目前仍高抗条锈病、对白粉病表现免疫。为了解其抗病基因,以云麦52为父本与感条锈病和白粉病的小麦不育系K78S杂交构建了F 2 群体,对双亲、杂种F 1 和F 2 群体的抗性鉴定结果表明,杂种F 1 对条锈病和白粉病均表现免疫,F 2 群体的白粉病和条锈病抗、感分离比经卡方测验均符合3:1,表明云麦52携带1个条锈病显性抗性基因和1个白粉病显性抗性基因。进一步用白粉病抗性基因Pm21的共分离标记SCAR 1400 和与条锈病抗病基因Yr26紧密连锁的标记XWe173和Xbarc181检测,亲本间和抗、感基因池间在相同位点上都扩增出多态性条带,用已知表型单株验证,表型与基因型极显著相关,SCAR 1400 、XWe173和Xbarc181检测准确率分别为100%、97.91%和92.70%,因此,云麦52的抗白粉病基因为Pm21,抗条锈病基因为Yr26,均来自于6AL/6VS易位系92R149。此外,该研究结果也证明Pm21和Yr26是具有持久抗性的抗病基因。

本研究以不同成胚率的3个小麦DH株系与同一玉米品种杂交,探讨简化去雄方法对成胚率的影响.2年的试验结果表明,常规去雄方法与剪药+喷水、剪颖不去雄、剪药+剪伤部分柱头等3种简化去雄方法的平均成胚率分别为26.53％、26.49％、27.84％和25.60％,4种处理间差异不显著;平均自交结实率分别为1.44％、2.35％、6.13％和3.12％,剪颖不去雄的自交结实率显著高于其他3种处理,自交结实率低的原因与授粉偏迟有关.与常规去雄相比,3种简化去雄方法的去雄效率高5倍以上且单倍体胚成胚宰相同,可作为小麦×玉米杂交中批量产生小麦单倍体的高效去雄方法单独或组合使用.

不育系的柱头外露是提高小麦异交结实率的关键因子之一.该研究以高柱头外露率的小麦温光敏核不育系K239S与低柱头外露率的不育系K92S杂交构建DH群体,对亲本、正反交F1和DH群体进行柱头外露率鉴定,结果正反交F1柱头外露率差异不显著,表明柱头外露受细胞核基因控制;DH群体低柱头外露率与高柱头外露率的分离比符合3:1,推测该小麦温光敏核不育系的柱头外露由1对隐性主基因控制.

A DH population derived from C49S-87 /01Y1-1069 was used to analyze the inheritance of wheat haploid embryo production frequency( EPF) in wheat × maize cross with the mixed major gene plus polygene genetic model of quantitative traits. The results showed that the EPF of wheat × maize cross was controlled by two dominant epistatic genes and polygene,with the gene effects of 1. 95 for the first major gene,6. 69 for the second one and 2. 80 for the polygene. The heritability of major genes was as high as 72. 09 %,suggesting that the differences of EPF among wheat materials were mainly influenced by genotype. However,non-genetic factors were still important,especially for wheat materials with low EPF.

The inheritance of wheat haploid embryo production frequency(EPF) in wheat × maize cross was investigated with a F2 population derived from C49S-87/01Y1-1069 by using the mixed major gene plus polygene genetic model of quantitative traits.The frequency distribution of EPF in the population showed characteristics of a mixed normal distribution,suggesting that the inheritance of EPF followed a major gene plus polygene model.And the model B6 was the most suitable one for the trait,i.e.the EPF was controlled by two co-dominance major genes,the heritability of major genes were lower at 43.6 %, indicating that non-genetic factors possibly had more influence on EPF in wheat × maize cross.

84 hybrid F1 were produced with 14 thermo-photo-sensitive genic male sterile wheat lines and 6 restorers by 14×6 incomplete diallel cross,for the purpose of evaluating the combining ability of male sterile lines.The general combining ability（GCA） and special combining ability（SCA） of male sterile lines were investigated on 7 traits.The results showed that the variances of GCA in grains per spike,1000-grains weight,spike length and spikelet per spike were significant at 0.01 level,suggesting that these four traits were mainly determined by additive effects,while the variances of GCA and SCA in yield per plant,spikes per plant and plant height were both significant at 0.01 level,indicating both additive and non-additive effects played important roles for these three traits.Parents with better GCA were generally characterized as having bigger GCA values in yield and yield components,and more yield components with positive GCA value,such as male sterile lines S1,S6,S7,S9,S12,S13 and S14.According to the analysis on SCA effects of yield component from top ten combinations with the highest SCA value for yield component,grains per spike was the most important component for combination with strong heterosis,then the spikes per plant and 1000-grain weight.The result is helpful not only for selecting combination,but also for breeding sterile lines and restorers.Moreover,the phenotypic values of spikelet per spike and plant height of male sterile line,spikes per plant,grains per spike,1000-grain weight and plant height of restorer,were all positively and significantly correlated with their GCA values,which meant the phenotypic values of these traits could be directly used as a guide to combination selection.

Effects of incising the tillering node of haploid seedling before treated with colchicine on the frequency of chromosome doubling were investigated.Results indicated that the pre-treatment of incising tillering node obviously increased the doubling frequency from 74.3 %(CK) to 90.3 %. According to the analysis of ear order beginning seed-set in 560 doubled haploids,only 31.1 % doubled plants begin seed-set from the main stem,most from the tiller ears,varying from the first to the thirteenth tiller,the total proportion of seeding from the top five ears were 82.1 %,that from the top seven ears were 94.3 %,suggesting that developing as many tillers and tiller ears as possible for haploid through cultivation before and after doubling was the guarantee of getting higher doubling frequency.

制种技术不够成熟是制约杂交小麦实现大面积生产应用的主要因素之一.云南省1997年以来的制种技术研究与生产实践表明,不育系的制种特性是建立温光敏两系杂交小麦制种技术的决定性因素；云南以选育具有优良制种特性的不育系为重点,将温光敏两系法制种程序简单的技术优势与优良不育系选育、组合筛选、制种栽培技术以及云南有利的自然条件紧密结合,建立了一套较简易、高效、实用的杂交小麦制种技术:即父母本同期分播、分收+人工辅助赶粉+常规小麦高产繁种技术；较好地解决了杂交小麦制种这一技术瓶颈问题,为杂交小麦较大面积的示范应用奠定了技术基础.