Development and validation of a quantitative PCR assay method of assessing relative resistance of oat (Avena sativa) to crown rust (Puccinia coronata f. sp. avenae)

Evaluation of oat crown rust resistance is usually based on visual assessment of disease severity or infection types. Visual assessment is subjective, prone to rater bias and requires expert knowledge. PCR-based quantitative assays can overcome challenges associated with visual assessment. New TaqMan primers and probes were designed from Puccinia coronata f. sp. avenae (Pca) sequences. The primer–probe sets were specific to Pca, amplified using as little as 0.5 pg fungal DNA (fDNA) and allowed for scaling to variation in sample total DNA quantity. The quantitative PCR (qPCR) assay was validated using oat recombinant inbred lines (RILs) from the Provena × 94197A1-9-2-2-2-5 cross evaluated under a controlled environment. For comparison with fDNA load, inoculation with the Pca race LCBB provided segregation data on the hypersensitive response, while Pca race LSLG provided data on segregation for reduced pustule number. fDNA content was positively correlated with both pustule number and infection type (IT). Composite interval mapping identified two quantitative trait loci (QTLs) on oat linkage groups Mrg12 and Mrg20 using visual and qPCR assessments (pustule number, IT and fDNA). In this study a qPCR assay method that can be used to assess the relative resistance of oat to crown rust was refined and validated, and single nucleotide polymorphisms (SNPs) closely linked with two QTLs derived from the crown rust resistant line 94197A1-9-2-2-2-5 were identified.     

Effects of S1-recurrent selection for protein yield on seven agronomic traits of oat

Summary Three S₁-recurrent selection programs (designated HG, HP, and HGP) for increasing protein yield of oat (Avena sativa L.) were conducted for five cycles of selection. The selection criteria in each program (line of descent) emphasized different components of protein yield; high grain yield in HG, both high protein concentration of the groats (caryopsis) and high grain yield in HP, and high protein yield per se in HGP. Heading date and height were restricted to no net change. The objectives of this study were to evaluate the agronomic performance of these three lines of descent and the correlated responses in agronomic traits due to selection. Thirty to sixty random S₀-derived lines from each cycle and ten check lines were grown in hill-plot experiments at two locations in 1989. Grain yield increased in all three lines of descent; HG showed the greatest rate of gain followed by HGP and then HP (0.20, 0.10, and 0.07 Mg ha^-1 per cycle, respectively). Test weight decreased in HGP by 2.6 kg m^-3 per cycle and in HP by 4.0 kg m^-3 per cycle, but remained constant in HG. Cycle 5 (C₅) means for straw yield, height, and seed weight were not significantly different from the C₀ means for any line of descent. Groat percent remained unchanged in HGP, increased from 70.1 to 71.7% in HG, and decreased from 69.9 to 67.6% in HP. Heading date decreased by 3 d in HG and HGP, but remained unchanged in HP. HG compares most favorably with commercial cultivars because of its high yield and acceptable agronomic traits, while HP tends to be low in test weight, seed weight, and groat percent.Abbreviations BM- above ground biomass - GP- groat (caryopsis) percent, fraction of average seed weight that is groat rather than hulls - GPC- groat-protein concentration - GPY- groat-protein yield - GTY- groat yield - GY- grain yield - HD- heading date - HG- selection for protein yield through high grain yield - HGP- selection for protein yield per se - HP- selection for protein yield through high grain yield and high groat-protein concentration - HT- height - PY- protein yield - SDWT- seed weight - SY- straw yield - TWT- test weight     

燕麦蛋白理化性质研究

以燕麦为原料,对碱提酸沉法提取的燕麦蛋白进行理化性质研究,分析了燕麦蛋白的溶解性、起泡性质、乳化性质、分子量分布、氨基酸组成和热变性。结果表明,在接近燕麦蛋白等电点处,溶解度最低,随pH增大溶解度逐渐升高。在等电点处,燕麦蛋白的起泡性最差,泡沫稳定性最好;偏离等电点燕麦蛋白的起泡性随着pH的增大先增加后减小,而泡沫稳定性稍有下降。燕麦蛋白的乳化性随pH的升高先减小后增大,在等电点附近乳化性最低;而乳化稳定性的变化规律正好相反。燕麦蛋白分子量分布主要集中在18.4~25.0 kDa和25.0~35.0 kDa 2个区间。燕麦蛋白氨基酸种类齐全,配比合理,是一种优质植物蛋白。运用DSC测出了燕麦蛋白的变性温度为102℃。     

高寒牧区燕麦人工草地的营养物质产量及其光能转化率

本文探讨了高寒牧区燕麦人工草地的营养物质产量动态、热值动态及其光能转化率。试验结果表明,燕麦草地地上部分的净营养物质产量为粗蛋白质89.63克/m²,粗脂肪30.33克/m²,无氮浸出物603.43克/m²,粗纤维331.80克/m²,粗灰分75.26克/m²,钙2.05克/m² 及磷1.35克/m²。以能量表示的燕麦草地全草层的净初级生产力为27229KJ/m²·年,为太阳总辐射的0.654%,其中地上部分为0.548%,地下部分占0.106%;对可见光生理辐射的转化率全草层为1.308%,地上部分为1.098%,地下部分为0.213%;对生长季生理有效辐射转化率全草层为2.083%,地上部分为2.351%,地下部分为0.456%。同时,作者探讨了燕麦草地的适宜刈割期。     

内蒙古土默川平原不同牧草产量与品质差异研究

以不同皮燕麦(Avena sativa L.)和苜蓿(Medicago sativaL.)品种为试验材料,采用田间随机设计,研究其草产量及品质差异,探讨其对内蒙古土默川平原的适应性.结果表明,皮燕麦的草产量、粗灰分含量均高于苜蓿;而粗蛋白含量则是苜蓿较高.表现较好的皮燕麦品种为蒙燕1号和坝燕4号.蒙燕1号的子粒产量较坝燕4号高(两品种分别为4 264.7、3 293.9 kg/hm2);而坝燕4号草产量较蒙燕1号高,其鲜草和干草产量分别高6 558.0、2 821.1 kg/hm2.苜蓿品种中紫花苜蓿是高产优质品种.     

添加剂对西藏燕麦和箭薚豌豆混合青贮发酵品质的影响

为评价乳酸菌制剂、山梨酸钾和糖蜜对燕麦与箭薚豌豆（7∶3）混合青贮发酵品质的影响,试验设对照组、乳酸菌制剂处理组（L）、0．15％山梨酸钾处理组（S）和3％糖蜜处理组（M）,分别在青贮后第30,45,60天开窖取样,测定青贮饲料发酵品质。结果表明,与对照组相比,3种添加剂均改善了混合青贮饲料发酵品质。其中乳酸菌制剂和糖蜜添加组乳酸含量、乳酸／乙酸显著（P＜0．05）高于对照组和山梨酸钾添加组,而青贮饲料pH、乙酸、总挥发性脂肪酸含量、氨态氮／总氮显著（P＜0．05）低于后两组。添加糖蜜对混和青贮饲料发酵品质的改善效果略优于乳酸菌制剂。山梨酸钾添加组乳酸含量、乳酸／乙酸显著（P＜0．05）高于对照组,乙酸、丁酸含量、氨态氮／总氮显著（P＜0．05）低于后者,但对青贮饲料pH、丙酸含量无显著（P＞0．05）影响。综上所述,3种添加剂添加效果依次为：糖蜜＞乳酸菌制剂＞山梨酸钾。     

裸燕麦新品种的经济性状和实用价值的研究

通过该项研究表明：内蒙古夏莜麦栽培区裸燕323的鲜草和籽实产量分别比对照（1）增产45．6％－67．7％，比对照（2）增产53．5％－26．3％；裸燕82比对照（1）增产41．7％－0．4％，比对照（2）增产49．1％－24．4％；将1季改2季栽培平均鲜草产量达139056kg/hm^2，比单季作增长1倍；在云南省冬季南繁中，在缩短日照条件下营养生长期加长，产草量更增大；在内蒙古冷凉秋莜麦区，裸燕323比对照（1）增产125％；在秋莜麦（高寒）区裸燕82比对照（1）增产29％，均表现适应性强，是粮草兼用的新品种，其营养成分高于对照种和玉米，是质优的饲用作物为养殖业奠定了物质基础；饲用后，每头牛日增奶量2．13kg,年增值1861．5元／头，栽培技术简便、成本低，减轻了农民投入和负担，增加的经济效益显著，是适宜推广的新品种。     

Mixing whole-crop pea–oat silage and grass–clover silage: positive effects on intake and milk production of dairy cows

Forty‐eight high‐yielding dairy cows of the Swedish Red breed were used to examine the effects of providing pea–oat silage (P), grass–clover silage (G) and a 0·50:0·50 mixture of the silages (M) ad libitum in diets with two concentrate levels (7 or 10 kg d^?1). A 9‐week experiment, including a 2‐week pre‐experimental period in which the cows were all fed the same diet, and an in vivo apparent digestibility study were conducted comparing the six dietary treatments (M7, M10, P7, P10, G7, G10). Intake and digestibility of the diets and milk production and live weight of the cows were measured. The G silage [11·3 MJ ME kg^?1 dry matter (DM)] was first‐cut grass herbage wilted for 24 h prior to addition of an additive, containing formic acid, propionic acid and ammonia, at 4 L t^?1 fresh matter (FM). The P forage was cut when the peas were at pod fill and ensiled directly with 6 L t^?1 FM of the same additive. The main hypothesis tested, that cows fed the M silage would produce more milk than the cows fed either the P or the G silages, was confirmed. The cows fed the M7 dietary treatment had similar milk yield and milk composition to cows offered the M10, G10 and P10 dietary treatments, and cows offered the G7 and P7 dietary treatments had lower milk and milk protein yields. This suggested that a mixed ration of pea–oat bi‐crop and grass–clover silage has a concentrate‐sparing effect, and that the use of pea–oat bi‐crop and grass–clover silage as a mixed ration for high‐yielding dairy cows can be recommended.     

间作模式对马铃薯叶片保护酶活性及产量的影响

于2016年与2017年在宁夏南部山区开展马铃薯‖燕麦田间试验,以单作马铃薯为对照,研究了4种马铃薯(P)与燕麦(O)间作行数比[2∶2(P2O2),4∶2(P4O2),4∶8(P4O8)]对马铃薯叶片保护性酶活性与产量的影响。2 a的试验结果表明,整个生育时期中P4O8处理的过氧化氢酶(CAT)和过氧化物酶(POD)显著高于其它间作处理(P0.05);马铃薯叶片超氧化物歧化酶(SOD)在块茎形成期最高;整个生育时期中,间作马铃薯叶片的丙二醛(MDA)高于单作(P0.05);与单作相比间作促进了马铃薯保护酶POD、CAT活性的增加。与单作相比,间作P4O2由于增加了商品薯数,减少了小薯数,从而显著增加了马铃薯产量(P0.05)。相关性分析表明,在马铃薯的整个生育时期中,POD、CAT和SOD均与马铃薯产量呈正相关关系;MDA与马铃薯产量呈负相关关系,马铃薯功能叶片膜脂过氧化程度越高,越不利于马铃薯的生长发育。马铃薯‖燕麦具有一定的优势,各间作处理土地当量比均大于1,这说明间作比单作的资源利用效率高;其中间作群体P4O2土地当量比(LER)最大,为1.21,其次是间作群体P4O8。综合来看,在马铃薯‖燕麦生产实践中,适宜采用4∶2(P4O2)的间作模式。     

导入燕麦DNA的小麦后代光合特性及农艺性状变化的研究

健壮燕麦(AvenasativaL.)总DNA通过花粉管通道导入普通小麦宁春4号,变异品系的光合特性及农艺性状发生变化:部分变异品系的旗叶功能期以及叶绿素含量改变,光合速率加快;穗长、结实小穗数、主穗粒数增加,穗粒重提高。方差分析表明,各变异品系与受体之间的叶绿素含量、光合速率及主要农艺性状均有显著差异。相关分析显示:自灌浆期起,变异品系的叶绿素含量与光合速率呈极显著正相关,在灌浆初期,叶绿素含量、光合速率均与结实小穗数、主穗粒数、穗粒重呈显著正相关。上述结果显示将燕麦DNA导入普通小麦,有助于小麦综合性状的改善,丰富小麦育种材料。