Morphological and cytogenetic studies on the hybrid between bread wheat and <Emphasis Type="Italic">Psathyrostachys huashanica</Emphasis> Keng ex Kuo

Psathyrostachys huashanica Keng ex Kuo (2n = 2x = 14, NsNs), a source of wheat stripe rust, take-all fungus, and powdery mildew resistance with tolerance to salinity and drought, has been successfully hybridized as the pollen parent to bread wheat without using immature embryo rescuing culture for the first time. All of the CSph2b × P. huashanica hybrid seeds germinate well. Backcross derivatives were successfully obtained. F₁ hybrids were verified as intergeneric hybrids on the basis of morphological observation, cytological and molecular analyses. The results obviously showed the phenotypes of the hybrid plants were intermediate between bread wheat and P. huashanica. Chromosome pairing at MI of PMCs in the F₁ hybrid plants was low, and the meiotic configuration was 26.80 I + 0.60 II (rod). Cytological analysis of the hybrid plants revealed the ineffectiveness of the ph2b gene on chromosome association between the parents. Eight RAPD-specific markers for Ns genome were selected for RAPD analysis, and the results indicated that F₁ hybrids contained the Ns genome of P. huashanica. Furthermore, the significance of the finding for bread wheat improvement was discussed.     

黄土高原地区蒙农4号新麦草的光合特征及其与环境因子间的关系

为研究蒙农4号新麦草(Psathyrostachys juncea‘Mengnong No.4’)在黄土高原地区的适应性,以美国引入新麦草为CK,用CI-340光合测定系统对其进行光合特性的测定,比较光合日变化,并分析其与环境因子的相关性。结果表明:2份材料的净光合速率(Pn)日变化均为双峰曲线,呈现出明显的"午休"现象,但蒙农4号新麦草的Pn最大值以及日均值均高于CK;2份材料的蒸腾速率日变化一样,为单峰曲线,最高峰出现在15:00左右。蒙农4号新麦草的气孔导度和叶片水分利用效率均高于CK,说明其适应性和生产力均大于CK。蒙农4号新麦草的光补偿点低而光饱和点较高,对光的适应性强,适合在黄土高原地区种植。     

新麦草新品系生物学特性及生产性能研究

对新麦草新品系及对照山丹新麦草的物候期、生长速度、草层结构、开花习性、产量性状等生物学特性和生产性能的研究结果表明,该品系具有抗寒、耐旱性强、返青早、生长发育快、青绿持续期长、分蘖多、须根系发达、开花整齐和产量高等优良特点,适宜于干旱半干旱地区栽培,具有很好的推广种植前景.     

卫星搭载对新麦草种子含水量的影响(简报)

卫星搭载是研究空间特殊环境(重粒子辐射、微重力等)对生物材料生长发育、生理生化及遗传特性的影响,同时还可以利用其产生的有益突变体对生物材料进行改良的研究^[1]。卫星搭载具有体积小、重量轻、忍受逆境能力强等优点,因而植物种子通常成为卫星搭载研究的首选材料。研究表明,胡枝子(Lespedeza bi-color)搭载后,当代植株中因而出现了矮化,早熟,黄化等变异性状^[2]。中国农业科学院畜牧所将野生沙打旺(Astragalus adsurgens P.)和卫星搭载的沙打旺进行杂交,获得性状优良的早熟品系^[1]。     

新麦草Psathyrostachys juncea遗传变异的细胞学和分子的分析

本文用染色体C分带、同功酶和RAPD技术分析了来自不同地理分布的新麦草不同材料的单株,观察其c带的多态性,即同源染色体的配对,相同材料的不同个体之间,同一地区不同材料之间,以及不同来源的材料之间的多态性。10个同功酶揭示了14个假定标记位点,其中11个显示了多态性(平均66.2％,每个位点具2.6个等位基因)。大量的等位变化发生在多数的多态位点上。在所用试材中有近90％的等位变化。在优化条件下,200个测试引物中有55.5％的材料间产生了多态性的RAPDs带型。在同一材料中和不同材料间分别有55.7％和47.8％的扩增片断是多态的。C—带、同功酶和RAPD分析结果是互相确证而高度一致的,为新麦草的遗传变异提供了模式。 新麦草具有抗旱、耐盐碱和抗黄矮病的特性,可以在小麦育种工作上加以利用。     

Production and cytogenetics of intergeneric hybrids between Triticum durum-Dasypyrum villosum amphidiploid and Psathyrostachys huashanica

Summary Intergeneric crosses between Triticum durum-Dasypyrum villosum (2n=42, AABBVV), and Psathyrostachys huashanica (2n=14, N ^h N ^h ) were made, the seed set was 1.67%. Intergeneric hybrid were successfully obtained by means of embryo culture for first time. The average chromosome pairing in the hybrid (ABVN ^h ) was 26.61% univalents, and 0.69 bivalents. The chiasmata per cell was 0.69. The chiasmata was higher than that in Triticum durum dihaploid (AB), and lower than that in T. durum-Dasypyrum villosum trihaploid (ABV). The result indicated that the N ^h genome of Psathyrostachys huashanica has no homology with the V genome of Dasypyrum villosum, and the A and B genomes of Triticum durum. The coenocytism, micronuclei cell and variation in chromosome numbers were also observed. The F₁ hybrid was crossed with Triticum aestivum (AABBDD), and resulted in seed set. The hybrid of T. durum-D. villosum amphidiploid x P. huashanica showed partial fertility. It made the possibility for chromosome manipulation among Triticum aestivum, Dasypyrum villosum and Psathyrostachys huashanica.     

华山新麦草籽粒硬度吲哚蛋白基因的分离与序列分析

采用AS-PCR技术,从华山新麦草基因组DNA中分离获得了其籽粒硬度吲哚蛋白Pina(HM 448475)和Pin b(HM448476)的基因序列.DNA序列分析显示,这2条序列相似性仅为69.25％,它们与小麦、山羊草、黑麦、燕麦和大麦亲缘种属植物等的Pin a和Pin b基因序列具有93％以上的一致性;推导的氨基酸序列分析显示,序列HM 448475(Pin a)和HM 448476(Pin b)都具有籽粒硬度吲哚蛋白基因的19个氨基酸残基组成的信号肽,与脂类易于结合的色氨酸结构域WRWWKWWK( Pin a)或WPTKWWK( Pin b),以及位置固定的10个半胱氨酸残基等典型结构特征,同时,这2条序列与小麦、山羊草等亲缘植物的Pin a和Pin b基因氨基酸相比,分别有15个和8个主要位点的差异;系统进化树分析显示,序列( HM 448475)可能为Pin a基因家族中的一个新类型,而序列(HM 448476)与智利大麦的Hordoindoline b基因具有相对较近的亲缘关系.研究表明,华山新麦草含有与麦类作物差异较大的控制籽粒硬度的等位基因.该研究对保护利用华山新麦草、丰富小麦籽粒硬度基因资源具有一定的理论意义和应用价值.     

秋水仙素处理山丹新麦草幼苗的染色体加倍研究

本文用不同浓度秋水仙素和不同处理时间对山丹新麦草幼苗进行染色体加倍研究。结果表明：最适宜的处理浓度和时间是0．10％的秋水仙素处理24h的四倍体诱变率最高,达62．5％。     

抗条锈病小麦-中间偃麦草-华山新麦草杂种后代的分子细胞遗传学鉴定

小麦近缘物种中蕴藏着许多优良基因,创制三属杂种是小麦遗传改良的重要途径.对4个F6代株系采用农艺性状调查、PMC染色体配对观察、GISH和SDS-PAGE等方法分析.结果表明,4个株系的染色体数目均为42条,K-13-649-3、K-13-663-2在细胞遗传学上相对稳定;且均确证为小麦-中间偃麦草易位系;K-13-649-3、K-13-728-4与亲本中3的特异条带一致,K-13-656-3、K-13-663-2只有3条条带,缺失了亲本中3的1条特异条带,4个株系表现为高抗条锈病.     

Production and characterization of an amphiploid between common wheat and Psathyrostachys huashanica Keng ex Kuo

Wide crosses and synthetic amphiploids have played an important role in introgressing desirable traits from related species into cultivated wheat. Hybrids between Triticum aestivum cv. 'J-11' and Psathyrostachys huashanica were treated with colchicine, to produce a new intergeneric amphiploid (PHW-SA). The morphological characteristics of PHW-SA resembled the parent 'J-11'. PHW-SA plants have purple internodes and pubescence in the basal spikelet, inherited from the P. huashanica parent. Somatic chromosome numbers varied from 2n = 51 to 2n = 56, with 70.59% of plants having 56 chromosomes. At metaphase I, PHW-SA (2n = 56) plants showed an average of 1.15 univalents, 27.34 bivalents, 0.03 trivalents and 0.02 tetravalents per cell; complete chromosome pairing occurred in 50% of the pollen mother cells. A survey of disease resistances revealed that the stripe rust resistance from P. huashanica was expressed, but powdery mildew resistance was suppressed. The fertility of PHW-SA was 60%.