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.

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.

K78S is a new sterile line transferred from C49S-87,a thermo-photo-sensitive genic male sterile wheat line introduced from Chongqing.In order to understand the inheritance of sterility of K78S,two DH(doubled haploid) populations DH-1 and DH-2,separately derived from F1 of K78S/1069 and C49S-87/1069,were constructed with wheat×maize system.And the fertility of DH plants was investigated in two sowing dates(Oct.15 and Oct.25,2007).The correlation coefficients of bagged seed-set rates for DH-1 and DH-2 between both sowing dates were 0.8050** and 0.7066*,respectively.Curve-flexion and Chi-square analyses indicated that the observed segregation of seed-set rates for DH-1 fits to a 1∶3∶3∶9 ratios in both sowing dates,suggesting the male sterility of K78S was controlled by two segregate recessive genes,the same result was got in first sowing date of DH-2,while in the second sowing,the ratio changed to 1∶15 because of the partial restoring of fertility for C49S-87 and the individuals,which meant two recessive genes were involved in the express of fertility of C49S-87.In addition,despite the difference in frequency distribution,the bagged seed-set rates for DH-1 and DH-2 varied at 0~99.1% and 0~98.8%,respectively,indicating minor genes also influence the fertility of K78S and C49S-87.

The wheat × maize system is one of the most effective ways to produce haploids in wheat. Whether and how it could be successfully applied in practical breeding mostly depends upon the efficiency of haploid embryo production. To perfect the protocols of haploid embryo induction, the efficiency of haploid embryo production between in vitro culture of cut plant and intact plant growth for hybrid spikes with two F 1 wheat hybrids and two maize varieties was compared. Effects of different cutting plant times and formulas of nutrient solutions for cut plant culture on haploid embryo formation were also studied. Results indicated that the embryo rate of in vitro culture was 3.29 times that of intact plant growth, with the figures of 31.6% vs 9.6%, respectively. The optimal time for cut plant culture was 24 h after pollination. Formulas of nutrient solutions significantly affected the efficiency of haploid embryo induction. With an embryo rate of 0–35.5%, adding calcium phosphate in the culture solution at 3 g·L −1 could raise the caryopsis and embryo rates. According to this study, the best medium for cut plant culture was: 100 mg·L −1 2,4-D+ 40 g·L −1 sucrose + 10 mg·L −1 silver nitrate + 8 mL·L −1 sulfurous acid + 3 g·L −1 calcium phosphate, with which a caryopsis rate of 95% and an embryo rate of about 30% could be obtained.

云杂5号是云南省农业科学院粮食作物研究所选育的温光敏两系杂交小麦组合,弱春性,有较强的抗寒性,分蘖力强,高抗条锈病和白粉病。通过对连续两年区域试验数据的产量、变异系数和回归系数分析,结果表明云杂5号的丰产性、稳定性和适应性均优于对照品种凤麦24号,具有高产潜力,是一个比较理想的高产抗病杂交小麦新组合。

<正>云南省农业科学院于1992年引进湖南和重庆的不育系材料开展研究,借助云南的生态优势,筛选出重庆温光敏核不育系C49S-87适于云南,以之组配的云杂3号(C49S- 87/98YR5)于2002年通过云南省农作物品种审定委员会

Using data of regional trial of thermo-photo sensitive two-line hybrid wheat in Yunnan province from 2002 to 2003,the productivity,stability and yield components of Yunza5 were analyzed with variation coefficient,regression coefficient,correlation analysis and path analysis.The results showed that the values of variation coefficient and regression coefficient in yield of Yunza5 was less than that of CK,suggesting Yunza5 was better in stability and adaptability compared with the CK.The values of variation coefficient of yield components were sequenced as follows: the number of effective ears(c.v.%=9.77)grains per ears(c.v.%=9.06)1000-grain weight(c.v.%=2.99).The values of correlation degree between yield and yield components were:1000-grain weight(r3y=0.9323)the number of effective ears(r1y=0.8821)grains per ears(r2y=0.7616).The direct effect of yield components on yield was: 1000-grain weight(P3y=0.4895)the number of effective ears(P1y=0.4715)grains per ears(P2y=0.1350).Therefore,the key to high yield cultivation of Yunza5 is adjusting and controlling the number of effective ear,then giving consideration to grains per ears and 1000-grain weight as well.

为充分利用温光敏两系杂交小麦的分蘖优势,降低杂交种的用种成本,对"云杂3号"最佳种植密度进行了研究.结果表明,4种基本苗(30×104/hm2、60×104/hm2、90×104/hm2、120×104/hm2)间产量差异不显著;但生育期随种植密度的下降而延长.从平衡用种成本和生产应用的角度考虑,在自然条件和栽培水平与昆明类似的生态区,"云杂3号"的最佳种植密度为基本苗90×104/hm2;在灌溉条件较好、栽培水平较高的地区,60×104/hm2的基本苗更能充分发挥"云杂3号"的分蘖优势,进一步降低用种成本.

In order to set up the techniques of thermo-photo sensitive two-line hybrid wheat seed production in Yunnan plateau,study on key technical measures concerned with purity and yield of F_1 hybrids were conducted in the F_1 seed production from 1997 to 2005 with two hybrid varieties Yunza 3(C49S-87/98YR5) and Yunza 5(K78S/01Y1-1069).Result showed that the row-ratio of male vs female had significant effect on seed yield,the optimum row-ratios of Yunza 3 and Yunza 5 were 2∶8 and 2∶6,respectively.When sterile line C49S-87 was used,the number of tiller spikes per plant should be controlled to less than 3 to guarantee the seed purity.And the leaf age,pulvinus distance and the length of young ear could be used as effective morphological indicators for predicting the flowering dates of male and female.In addition,practices from seed production with C49S-87 and K78S indicated that fertility parameters and outcrossing ability of sterile line play decisive role in determining the technicals and effectiveness of hybrid seed production.Since 2003,one set of simple,highly effective and low cost techniques for hybrid seed production based on thermo-photo sensitive genic male sterile(TPSGMS) line K78S were established,with average hybrid seed yield of 3 750 kg/hm~2(except male yield in the area) and of purity 98% in practical application of hundreds of hectares.

Two-line hybrid wheat(Triticum aestivum L.),created with Thermo-Photo-Sensitive Genic Male Sterile(TPSGMS) line,has become one of the main ways studied in China in heterosis utilization of wheat since 1992,as TPSGMS wheat C49S and ES series were bred.In 2002,first hybrid wheat combination Yunza 3(C49S87/98YR5) was registered and released in Yunnan.Simultaneously,the improved second generation of TPSGMS lines K78S derived from C49S-87 was developed in 2001,Yunza 5(released in 2004) and Yunza 6 were also developed subsequently.In order to determine the suitable hybrid seed production region of K78S,the investigation of fertility was conducted in 5 different ecological regions with altitude of 1 5302 400 m from 2001 to 2004 in Yunnan.The results showed that K78S was adaptable in all theses areas with the sowing period from middle October to early November,bagged sterile rates98%,and sterile duration of 1843 d(18 d longer than C49S-87),indicating that the hybrid seeds could be produced safely in these areas.Observation of abortive pollen in Kunming indicated that K78S was better in pollen sterile rate and fertility stability than C49S-87,and for 19 times of observation from Jan.31 to Apr.1,95.96% of abortive pollens in K78S were round or typical abortion types,only 4.04% the stainable abortion;while in C49S-87,the figures were 77.68% vs(22.32%,) which meant the pollen abortion in K78S was more complete than that in C49S-87.Preliminary analysis of the critical sterile thermo-photo values for fertility alteration indicated that K78S was 2.1℃ higher in critical temperature and 0.93 h longer in daylength than C49S-87,which proved that K78S has wider adaptability and broader planting area suitable for hybrid seed production in Yunnan.

In order to set up the protocols of wheat×maize for wheat breading and genetic analysis,22 sowing dates of 6 wheat materials and 11 sowing dates of 3 maize varieties were conducted in the field from February 9 to August 22,2003 in Kunming,and the crosses of wheat×maize were made.Results showed that there were 6 months to conduct wheat×maize in natural conditions of Kunming every year from middle May to middle October.In pollination,'rolling pollens',a modified method of pollinating by rolling one or several emasculated wheat ears into the collected fresh maize pollens,was adopted because large amount of maize pollens could be collected,which obviously raised the effectiveness of pollination at about 10～15 spikes/min per person,and the rate of caryopsis could be up to(88.77%)～98.4%.The average daytime relative humidity (RH) of atmosphere in 10 days after pollination had significant effects on caryopsis and embryo rates,on average,88.77% and 58.45% of caryopsis rate,19.94% and 6.55% of embryo rate were achieved under lower(RH70%) and higher relative humidity(RH85%) respectively.The optimum time for harvesting spikes under natural conditions in Kunming was at 17～19 d after pollination,when 80% of haploid embryos were larger than 0.5mm in diameter,with preliminary differentiation in some bigger ones.And haploid embryos produced in plump caryopses was 2.95 times of that in shrivelled or blighted ones,24.8% and 8.4%,respectiveoly.Haploid seedlings with 2 leaves could be transplanted into field whenever produced in Kunming all the year and double haploid seeds from plants treated with colchicine could be harvested from September to November if crosses were made between middle May to middle June.Therefore,the natural conditions in Kunming could provide good conditions for mass production of haploid wheat plants induced with maize pollen.

为了提高小麦×玉米的单倍体胚诱导频率,以玉米品种"白甜糯"和4个小麦品系为材料,研究了小麦不同穗位、不同发育进度的小花对小麦×玉米单倍体胚诱导频率的影响.结果表明,授粉时小麦小花的发育进度对颖果结实率和单倍体胚诱导率有明显影响,单倍体胚诱导率以处于盛花期的小花最高(平均为22.3%),初花期次之(16.4%),始花期最低(11.3%);在同一个穗子中,中、上部小花的单倍体胚诱导率(24.2%、26.8%)显著高于下部小花(18.5%),说明在小花柱头发育较成熟时授粉,有利于提高单倍体胚诱导率.研究结果还表明,主穗小花的单倍体胚诱导率与次生分蘖穗间差异不显著.

By consecutive fertility selection in both winter and summer sowing seasons started from F 2 generation,two thermo photo sensitive genic male sterile(TPSGMS)lines K78S and K1564S were bred using TPSGMS wheat C49S 87 with weak restoring ability as male parent,and 96B 138 as the female parent The 2 accessions were characteristic by more adaptable to plateau climates and insensitive to larger temperature differences between day and night,stronger and longer sunlight compared with C49S 87 Results from fertility studies also showed that these two lines,with improved resistance to stripe rust and better out cross ability,had at least 15 days longer sterile durations than C49S 87,which guaranteed the safety of hybrid seed production in most areas of 1600?m above sea level in Yunnan

对温光型两用核不育系C49S-87和6个云南典型恢复系剑叶平展-抽穗-开花各发育阶段作了比较研究.结果表明,高原生态条件下C49S-87与恢复系在剑叶平展后至开花期间具有不同的阶段发育进度,但只要父母本主穗和群体剑叶平展时期基本一致,后期不需对花期进行大的调节即可达到花期相遇.因此,剑叶平展期可作为制种中后期花期预测的一个主要形态指标.