A new cytoplasmic-nuclear male sterility system in pearl millet

Among the cytoplasmic-nuclear male sterility (CMS) systems reported in pearl millet, Pennisetum glaucum (L.) R. Br., the A_m= A₄ system produces the highest frequency of male-sterile hybrids. A CMS source identified in a large-seeded gene pool (LSGP) was compared with the A₄ system. Seven diverse restorer lines of the A4 system produced hybrids with 81A4 that were all fertile (pollen-shedding score 4 and 68–89% selfed seedset). In contrast, all the hybrids of these inbreds made with the isonuclear line with the LSGP cytoplasm were sterile (pollen-shedding score 1 and 0–3% selfed seedset). Topcross hybrids of four diverse composites made with 81A4 had 10–35% plants that had good fertility (> 50% selfed seedset). In comparison, no plant of any topcross hybrid with the isonuclear line having LSGP cytoplasm exceeded 20% selfed seedset, and it was rare for a plant to exceed even 10% selfed seedset. These differential fertility restoration patterns of hybrids indicate that the LSGP cytoplasm represents a CMS system that is different from the A4 and, by implication, from all those reported to date. This new CMS system is designated A₅.     

杂交狼尾草种茎越冬繁殖技术研究

[目的]探讨杂交狼尾草的越冬保存及越冬方式对生长发育的影响。[方法]以一年生杂交狼尾草的根茎为试料,采用3种越冬方式(露地留茬、种茎坑埋、种茎带根地窖储藏),观察杂交狼尾草越冬效果和生长发育情况,研究了杂交狼尾草根茎越冬繁殖特性及不同越冬方式对其生产性能的影响。[结果]杂交狼尾草根茎越冬适宜采用坑埋或地窖储藏方式,成活率分别为89.60%±1.790%、76.9%±1.69%,二者差异不显著(P>0.05);种茎带根地窖储藏育苗成活率为79.40%±2.25%,极显著高于种茎坑埋(P<0.01);种茎带根和不带根成活苗移栽大田后,刈割次数均为4次,但2种苗的分蘖数、产量差异显著(P<0.05)。[结论]该研究为杂交狼尾草的越冬保存提供了科学依据。     

Effects of Shading and Regaining Natural Light Treatment on Leaf Color and Physiological Changes of Pennisetum setaceum 'Rubrum'北大核心CSCD

To explore the effect of light on the leaf color and physiological changes of Pennisetum setaceum 'Rubrum', the natural light was used as a control, and the shading net with 10% transniittance was used to shading the new leaves until the new leaves fully devloped. Then, remove sun-shade net and using natural light for re-lighting treatmetn. And then the dynamic changes of leaf color parameters and related physiological indexes at different development stages were measured. The results showed that the new leaves of Pennisetum setaceum ' R u b r u m ' were green after shading, and the leaf color parameters L and b values were increased significantly, and the value of a decreased significantly. The contents of chlorophyll a and chlorophyll b were increased significantly, while anthocyanin, flavonoid, soluble sugar content and phenylalnine ammonialyase, chalcone isomerase activities were significantly decreased. The polyphenol oxidase and peroxidase activities were not changed significantly. After the re-lighting treatment, the leaf color gradually turned purple, and the leaf color parameter changed opposite to shading treatmetn. The change of physiological indexes was opposite to the decrease or increase after shading. The PPO and POD activities were not significantly changed, either. © 2019 China Agricultural University. All rights reserved.     

热研4号王草和桂闽引象草的核型分析

采用常规压片法,对热研4号王草(Pennisetum purpureum×P.americanum cv.Reyan No.4)和桂闽引象草(P.purpureumcv.Guiminyin)的染色体数目和核型进行分析,以期为狼尾草属种质资源多样性保护利用和遗传育种研究提供理论依据。结果表明,两者染色体基数均为x=7。其中,热研4号王草为三倍体,有21条染色体,核型公式2n=3x=21=21m(3SAT),染色体相对组成I.R.L=9S+3M1+3M2+6L,3条染色体含有随体;桂闽引象草为四倍体,有28条染色体,核型公式2n=4x=28=18m(2SAT)+10sm(2SAT),染色体相对组成I.R.L=10S+6M1+4M2+8L,4条染色体含有随体。热研4号王草和桂闽引象草核型不对称系数分别为60.15%和62.19%,属于1B型和1C型,其核型都属于比较原始的类型。     

巨菌草诱导培养基的筛选及优化

巨菌草(Pennisetumsp.)属单子叶禾本科狼尾草属植物,可作为动物饲料和多种食用菌的培养基质,在中国及非洲广泛种植,然而不耐寒的特性限制了其推广应用。要克服其遗传缺陷,需借助转基因或体细胞杂交等技术,因此,必须建立巨菌草的组织培养体系。本研究以巨菌草幼茎为材料,研究了巨菌草外植体的消毒方式和2,4-D、IAA与NAA,细胞分裂素(6-BA和KT)的不同浓度及组合对愈伤组织诱导的影响。结果表明,用75%酒精擦拭剥离后的叶鞘,再用2%的次氯酸钠溶液消毒10 min就能达到理想的消毒目的。1.0~4.0 mg·L-1的2,4-D都可以诱导出愈伤组织,且各浓度间无显著差异(P0.05);0.2mg·L-1 IAA对愈伤组织诱导有较好的促进作用;不同细胞分裂素对愈伤组织诱导没有明显促进作用。巨菌草愈伤组织诱导的最佳培养基配方是MS+2,4-D(3.0mg·L-1)+IAA(0.2mg·L-1)。     

杂交狼尾草宁牧3号区域试验总结报告

在四川雅安对宁牧３号杂交狼尾草进行了区域试验，结果表明该品种产草量、种子收获后秸秆产量和抗逆性等均优于对照狼尾草品种宁牧２６－２，产草量（干重）比对照稳定增产在２０％以上，可望在四川各地推广利用。     

杂交狼尾草制造刨花板工艺研究

该文研究了以杂交狼尾草为原料的刨花板制造工艺。杂交狼尾草通过削片、再碎、干燥等加工制成工艺刨花,以三聚氰胺改性脲醛树脂为胶粘剂,采用正交实验设计,研究施胶量、偶联剂量、热压温度等工艺因素对刨花板主要物理力学性能(静曲强度、弹性模量、内结合强度、吸水厚度膨胀率)的影响,确定热压工艺条件。研究表明:①杂交狼尾草可以用于刨花板制造。②三聚氰胺改性脲醛树脂可以用于杂交狼尾草刨花板制造。③最佳工艺参数:施胶量10％,偶联剂量0.5％,热压时间50 s/mm。      

云南德宏地区逸生狼尾草属植物的分类学鉴定

采用传统分类学,细胞学和RAPD分子标记对云南德宏地区逸生狼尾草(Pennisefum Rich.sp.)进行分析和鉴定。结果表明:逸生狼尾草体细胞染色体数为2n=28,经同工酶及RAPD分析,逸生狼尾草与矮象草(P.purpureum Schum.cv.Mott)的遗传距离较近,而与王草(P.americanum×P.typhoideum)的遗传距离较远,说明逸生狼尾草在分类上属象草,而非当地多年称谓的"狼尾草"。     

41%异丙草-莠悬乳剂防除狼尾草田杂草效果初报

采用田间小区试验方法,研究了41%异丙草－莠悬乳剂对夏播狼尾草田杂草的防除效果。结果表明,41%异丙草－莠悬乳剂可有效防除狼尾草田的马唐、马齿苋和反枝苋等杂草,但对狼尾草的生长有一定不利影响。在考虑降低成本和保证饲草安全前提下,于狼尾草播种出苗后5d,用41%异丙草－莠悬乳剂2.250L/hm2,兑水稀释后均匀喷雾于地表面,可收到较好的除草效果。     

红色狼尾草的离体培养及产业化生产

利用红色狼尾草的茎段和顶芽为外植体对其进行快繁研究,结果表明,顶芽、节段0.1%HgCl2灭菌11～12min获得的无菌材料最高,分别为75%、90%;诱导培养基MS+BA1.0+NAA0.1顶芽、茎段出芽率90%以上;适宜的增殖培养基MS+BA+NAA+PP333,其增殖率在4.0;BA对其增殖率有明显效果,蔗糖、盐离子浓度对生根有影响,加入PP333可有效抑制增殖、生根的徒长,培养基1/3MS+BA+NAA+PP333+蔗糖60g.L-1为最佳组合,并建立了商业化的生产工艺体系。