杂交授粉方式对玉米与大刍草远缘杂交结实率的影响

为了提高玉米与大刍草远缘杂交结实率,通过方差分析和多重比较等方法,研究不同杂交授粉方式对玉米与大刍草远缘杂交结实率的影响。结果表明：玉米与大刍草杂交,因受体材料（母本）基因型不同,以及采用不同的杂交授粉方式,杂交结实率会有明显差异。重复授粉、剪短雌穗顶部苞叶及花丝、喷施赤霉素等处理后授粉均极显著提高玉米与大刍草杂交结实率,且前2种处理杂交结实率显著高于后一种处理。因此,要提高玉米与大刍草杂交选育的饲草玉米制种产量,除注重对母本基因型选择外,还应采用重复授粉、剪短雌穗顶部苞叶及花丝后授粉等方式。     

对玉米起源进化及现代玉米诸多返祖现象的研究探讨

用大刍草作受体和现代玉米杂交,对产生的"中间型"种子进行种植观察,其后代出现分蘖、分枝、多穗;由此我们认为玉米的进化过程是:分蘖→分枝→多穗→现代玉米;现代玉米出现分蘖、分枝、多穗均属"返祖现象"。     

CIMMYT牧草与普通玉米杂交后植物学形态变异研究

[研究目的]为发掘利用CIMMYT牧草生长繁茂和抗逆能力强等优良遗传特性,改良普通玉米材料的抗逆性和创制新型饲草材料.[方法]以CIMMYT牧草和4个普通玉米自交系为遗传交配材料,比较研究了CIMMYT牧草和4个杂交(回交)后代材料的植物学形态特征及其与普通玉米的差异.[结果]CIMMYT牧草能将其生长繁茂、分蘖力强、生物产量高的特性遗传给杂交后代材料,并有较强的世代传递能力;该牧草幼苗、植株及其生长习性、花器官、种子特征等与普通玉米差异明显,其与普通玉米的杂交后代基本保持了它的生长发育特性,但花器官和种子特征更偏向于普通玉米;回交后代除保持了一定的分蘖特性、明显的多穗和返祖现象外,其余特征特性与普通玉米基本没有区别.[结论] CIMMYT牧草生长繁茂和生物产量高的特性能遗传给杂交后代,世代传递能力较强,通过遗传改良途径,能将CIM-MYT牧草的优良特性转育到普通玉米中,培育出饲草玉米育种新材料.     

几种饲草作物的饲用品质及产草量比较试验

在河北平原农区夏播条件下,通过对5种饲草作物的饲用品质、生长特性以及鲜草、干草、粗蛋白产量的研究分析表明:表现最好的为杂交狼尾草,其鲜草、干草、粗蛋白产量均高于其他品种;其次为高丹草,其鲜草、干草、粗蛋白产量也都明显高于青贮玉米。而且杂交狼尾草和高丹草可以替代青贮玉米与冬小麦实现一年两作,两种饲草的分蘖力、再生性较强,夏播可以进行两次刈割。因此杂交狼尾草和高丹草可以在河北平原农区进行推广应用。     

多棱饲用大麦品系粮、草产量及品质的鉴定与综合评价

为培育适宜沿江、江淮地区种植的粮（籽粒）和草（饲草）产量及品质优良的大麦新品种，对12份多棱饲用大麦新品系和对照品种西引二号的饲草和籽粒的产量及品质进行比较，运用灰色关联度分析法进行综合评价。结果表明，B11015-1干草产量显著高于大部分自育品系，但与对照差异不显著；多个自育品系的籽粒产量高于对照，其中B11015-7籽粒产量最高；B11015-7和B11015-3饲草粗蛋白含量较高，分别为7.96%和7.82%；B11015-2和B11015-14相对饲喂价值（RFV）较高，分别为159.15和157.14；B11015-3和皖饲2-1籽粒蛋白质含量较高，分别为10.33%和10.03%。采用灰色关联度分析，以10个性状指标对参试品种（系）进行综合评价，初步认为B11015-3、B11015-1、B11015-2和B11015-14等4个自育品系优于对照，可能成为沿江、江淮等地种植的粮、草兼用多棱饲用大麦材料。     

番茄品系遗传多样性的品质试验分析

对12个品系进行种间、种内变种间、变种内不同选育方式间、变种内不同果实形状间在果实营养品质（果实维生素C含量、可溶性固形物含量、干物质含量和糖酸比）上的差异进行分析,采用统计学上单一自由度正交比较分析法与植物学分类相结合的方法进行分析,结果表明：醋栗番茄种品系YH02-12在4个营养品质性状上,极显著高于普通番茄种品系;樱桃番茄变种品系在4个营养品质性状上的平均水平极显著或显著高于普通番茄变种品系的平均水平;2个空间诱变品系YH02-2、YH02-6在4个营养品质性状上均极显著高于同变种的其他品系的平均水平;樱桃番茄变种品系中,梨形果品系YH02-5、YH02-8的果实维生素C、可溶性固形物含量均极显著地低于樱桃番茄变种中圆形或李形品系的平均水平,李形果品系YH02-9在4个营养品质性状上均极显著地高于圆形果品系的平均水平,黄色圆形果品系YH02-11的果实维生素C偏低于红色圆形果品系YH02-1和YH02-7。由此可得出结论：品质较好的品系为YH02-12、YH02-2、YH02-6和YH02-9,樱桃番茄变种品系在4个营养品质上优于普通番茄变种品系,梨形果品系相对于其他樱桃番茄变种品系在这4个营养品质上表现较差     

墨西哥玉米草优12无公害栽培技术

<正>墨西哥玉米草优12,为禾本科大刍草属一年生草本植物。原产于拉丁美洲北部墨西哥。该品种叶片宽长肥厚、脆嫩光洁、味甜多汁,营养丰富,消化率高;生长期长,产量高;耐酸、耐肥、耐热,是饲养牛、羊、兔、鱼、猪的上佳青饲料。上杭县2008年引进种植墨西哥玉米草优12,表现喜温耐肥,适应性强,根系发达,茎秆粗壮,分蘖(枝)和再     

野生鸭茅与栽培品种杂交后代农艺性状初步研究

以波特鸭茅为对照,初步研究了野生二倍体鸭茅诱导的同源四倍体与鸭茅栽培品种杂交后代的生长速度、再生特性、干物质产量以及生殖枝比例等主要农艺性状.结果表明:(1)杂交后代之间存在着丰富的变异.生长速度随着温度的下降而缓慢下降.材料157四次刈割生长速度与再生率均高于波特,具有较强的生长及再生优势;(2)37-4 F1-1、37-4 F1-4的分蘖能力较强,10月份的分蘖数达到145.20、117.60,4次刈割总产量分别为81.41 g/株、81.97 g/椿,是杂交后代中分蘖及产量性状均比较优良的材料;(3)各农艺性状之间存在一定的相关性,研究早期可通过分蘖数判断产量.     

远缘杂交与半配合育种相结合培育彩色棉

用激素处理和染色体加倍的方法获得彩色棉远缘杂交后代,结合杂交、回交、聚合杂交的手段,使彩色棉材料的品质性状得到了显著的提高。为了使新品系的性状尽快稳定,通过半配合材料VSG作母本与之杂交,得到彩色棉的单倍体,通过染色体加倍等手段得到了稳定的优质彩色棉新品系。     

密度和施氮量对玉草3号产量及品质的影响

为明确乌鲁木齐北郊饲草玉米玉草3号的适宜施氮量,研究了3种栽培密度和4种施氮水平下玉草3号的饲草产量和主要营养成分含量。结果表明,玉草3号的鲜草产量最佳密度和施氮量组合为低密度(50000株/hm~2)和低氮水平(100kg/hm~2纯氮),此时鲜草产量最高,为112320kg/hm~2,而该密度下不施氮(0kg/hm~2纯氮)鲜草产量为109155kg/hm~2,与最佳密度和施氮量组合无显著差异。低密度有利于分蘖型玉草3号发挥其生产潜能。随着施氮量的增加,粗蛋白含量总体呈略微增加的趋势,但不同施氮量间无显著差异。玉草3号饲草品质(粗蛋白、中性洗涤纤维、酸性洗涤纤维)不受密度和施氮量的影响,饲草主要营养成分在各处理下表现稳定。玉草3号在低密度50000株/hm~2和施氮100kg/hm~2(纯氮)水平下生产,可以获得较高的生物产量并不降低饲草营养水平,是该区域推荐的密度和施氮量水平。     

Hybrid and N Fertilization Affect Corn Silage Yield and Quality

We determined the effect of N fertilization on dry matter (DM) yield, predicted milk yield, and forage quality of fresh (green chopped) and ensiled forage of two brown midrib (BMR) hybrids, a leafy hybrid, and a conventional silage hybrid. Increasing N rates from 0 to 200 kg ha^?1 increased corn grain, stover and whole plant DM yield and milk yield. The forage yield and quality response to N was similar for all hybrids. Nitrogen fertilization increased forage crude protein (CP) concentration but had little effect on other forage quality components. BMR hybrids, F377 and F657, had the lowest grain, stover and whole plant yield but had the highest digestibility and predicted milk yield Mg^?1 of forage. Predicted milk yield ha^?1 was similar for the BMR, leafy and conventional hybrids. Ensiling reduced starch concentration compared with green chopped forage, but effects on other forage quality variables were less consistent. Hybrid and N fertilization affects were similar for green chopped and ensiled corn forage.     

内蒙古农牧交错区生态因素对玉米生长发育和饲用品质的影响

选择内蒙古从东到西5个典型生态类型区,通过不同玉米品种的比较试验,对不同生态区玉米全生育期内生态因素与玉米生长发育和全株饲用品质的关系进行系统研究,结果表明:玉米产量主要与地区温度和降水有关;不同生态区间按照温度升高,降雨量递减的顺序,玉米生育进程渐次加快,植株营养体增高,保绿性增强,籽粒产量和生物产量增大;玉米全株粗蛋白、粗脂肪、总消化养分和各能量指标含量降低,而粗纤维、粗灰分和无氮浸出物含量增高;粗蛋白、粗纤维、粗灰分、无氮浸出物和总消化养分群体积累量增大,而粗脂肪和能量积累量相反.不同生态区玉米生育期间日均温度、有效积温、平均日长和降雨量与玉米全株营养品质间可以通过线性回归较好拟合,方程可以反映各生态因子与玉米全株饲用品质的正负效应和定量关系,为各生态区根据当地生态因素预测玉米饲用品质、指导玉米青贮利用提供理论依据.     

Evaluation of the contribution of teosinte to the improvement of agronomic,grain quality and yield traits in maize (Zea mays)

Teosinte, an ancestor to modern maize, displays an excellent performance regarding resistance to stress, but its yield potential has rarely been reported. To evaluate the potential contribution of teosinte to maize improvement, two maize–teosinte backcrossed recombination inbred line (RIL) populations and their corresponding test-cross hybrids were planted for trait assessment. In RN and ZP RIL populations, the average coefficients of variation of 31 agronomic traits were 9.14% (Range, 0.38%‒25.21%) and 6.85% (Range, 0.55%‒27.73%), respectively. The correlation coefficients of 13 common shared traits between RIL populations and test-cross hybrid populations ranged from 0.10 to 0.60 and from 0.06 to 0.72, respectively. A total of 39 and 3 recombined inbred lines, and 29 and 47 test-cross hybrids exhibited higher yields than their checks (RP125, Zheng58, CD189 and ZD958) with the BLUP data, respectively. Furthermore, four test-cross hybrids including RN034/SCML1950, ZP068/Chang7-2, ZP079/Chang7-2 and ZP122/Chang7-2 showed a more stable yield performance, with yield gains of +7.07%, +3.64%, +5.83% and +3.82% over checks, respectively. In conclusion, teosinte could serve as an alien germplasm for maize breeding.     

Alternate Row Spacing and Plant Density Effects on Forage and Dry Matter Yield of Corn Hybrids (Zea mays L.)

Irrigated field experiments were conducted in the Marmara region of Turkey in 2002 and 2003 to compare alternate 40 : 25 cm row spacings and conventional 65 cm with four different plant densities (65 000, 85 000, 105 000 and 125 000 plants ha⁻¹) of three corn hybrids (DK-585, ADA 95–10 and C-955) in some morphological traits and forage and dry matter yield. Morphological traits such as plant height, leaf per plant, stem diameter, ear per plant and ear percentage were measured, forage and dry matter yield was also determined in this study. Hybrids, row spacings and plant densities significantly affected some morphological traits, forage and dry matter yield at 0.01 level. Later maturing hybrids tended to produce taller and thicker stemmed plants. Row spacings and plant densities did not affect plant height. Average stem diameter increased significantly with population density. Row spacings did not influence leaf number, whereas leaf number increased slightly with plant density. On average, all corn plants had slightly more than 1.0 ear per plant in our experiment. Row spacings and plant densities did not affect significantly number of ear per plant. Early maturing DK-585 had the highest ear percentage whilst late maturing C-955 lowest. Yields usually increased with hybrid maturity. When averaged across years, row spacings and plant densities, late maturing C-955 performed significantly better in forage and dry matter yield in all experimental years and combined years. The studies showed favourable advantage for alternate 40 : 25 cm rows over conventional 65 cm row spacings at all plant densities. Average forage and dry matter yields were greater for alternate 40 : 25 cm row spacings than for 65 cm row spacings. However, strong hybrid × row spacing interactions for both forage and dry matter yield were detected.     

Potassium Management for Brown Midrib Sorghum × Sudangrass as Replacement for Corn Silage in the North-eastern USA

In recent years, there has been a growing interest in brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanense Piper) hybrids (SxS) as a replacement for silage corn (Zea mays L.) in the north‐eastern USA. Recent studies suggest it is suitable for both rotational grazing and as a hay crop and could compete with corn harvested for silage in years when wet spring conditions prevent the timely planting of corn. However, little is known about its suitability as forage for non‐lactating cows that require low potassium (K) forages to prevent health problems. Our objective was to evaluate the impact of K fertilizer management (0, 112 or 224 kg K₂O ha^?1 cut^?1) under optimum N management (112–168 kg N ha^?1 cut^?1) on yield, quality and K concentrations of BMR SxS over a 2‐year period. Field trials were established on a fine loamy, mixed, active, mesic Aeric Fragiaquepts with medium K‐supplying capacity and characteristic of a large region in New York. Potassium application did not affect dry matter yields in either of the 2 years. Averaged over 2 years, neutral detergent fibre (NDF) significantly increased with K addition with similar but non‐significant trends observed in each of the years individually. The digestibility of NDF was unaffected by K application. Crude protein (CP) concentrations showed a significant decrease with K application in 2002 and similar trends were observed in 2003, although differences were not significant at P ≤ 0.05. The changes in NDF and CP did not significantly impact forage quality expressed as milk production per megagram of silage. Potassium application increased forage K concentration up to 13 mg K kg^?1 dry matter (in the first cut in 2003). Forage Ca and Mg concentrations decreased with K addition except for the first cut in 2002 where differences between 112 and 224 kg K₂O ha^?1 treatments were not significant. Without K addition in the 2‐year period, K concentrations in the forage decreased from 23 g kg^?1 for the first cutting in 2002 to 15 g kg^?1 for the second cut in 2003. Low K forage was obtained for all second‐cut forage unless 224 kg K₂O ha^?1 cut^?1 had been added. First‐cut forage was suitable only when no additional K had been applied. These results suggest low K BMR SxS forage can be harvested from initially high K soils without loss in dry matter yield as long as no additional K is added.     

高梁、苏丹草及高梁-苏丹草杂交种产量和饲用品质的比较

在大田条件下，比较研究了高梁-苏丹草杂交种（皖草2号、京科草1号）与高梁、苏丹草的生物产量和饲用品质。结果表明，与高梁和苏丹草相比，高梁-苏丹草杂交种的生物产量高，其中，皖草2号的鲜、干物质产量比苏丹草722选分别高83．8％和121．9％，京科草1号的鲜、干物质产量比722选分别高98．6％和139．9％；杂交种的粗蛋白、粗脂肪含量高，无氮浸出物含量低；粗蛋白、粗脂肪和粗纤维的产量及总能量均最高，高梁次之，苏丹草最低，杂交种饲用品质的改善主要是粗蛋白和粗脂肪的显著提高；从物质分配和能量形成的角度分析，茎秆和叶鞘是鲜物质产量的主要组成部分，而在干物质产量和能量的形成过程中，茎秆、叶鞘和叶片具有同等重要的作用。     

高粱、苏丹草及高粱-苏丹草杂交种产量和饲用品质的比较

在大田条件下,比较研究了高粱-苏丹草杂交种（皖草2号、京科草1号）与高粱、苏丹草的生物产量和饲用品质。结果表明,与高粱和苏丹草相比,高粱-苏丹草杂交种的生物产量高,其中,皖草2号的鲜、干物质产量比苏丹草722选分别高83.8%和121.9%,京科草1号的鲜、干物质产量比722选分别高98.6%和139.9%;杂交种的粗蛋白、粗脂肪含量高,无氮浸出物含量低;粗蛋白、粗脂肪和粗纤维的产量及总能量均最高,高粱次之,苏丹草最低,杂交种饲用品质的改善主要是粗蛋白和粗脂肪的显著提高;从物质分配和能量形成的角度分析,茎秆和叶鞘是鲜物质产量的主要组成部分,而在干物质产量和能量的形成过程中,茎秆、叶鞘和叶片具有同等重要的作用。     

Response of Corn Hybrids Differing in Canopy Architecture to Chemical and Mechanical (Rotary Hoeing) Weed Control: Morphology and Yield

Weed interference with the growth and yield of corn plants is affected by both mechanical and chemical means of weed control. Recently, corn hybrids accumulating more leaf area, maturing earlier, yielding better in narrower row spacings and tolerating higher plant populations better than conventional hybrids have been developed. Because of more rapid leaf area accumulation during the earliest stages of canopy development and overall canopy architecture, they may be more susceptible to damage due to mechanical weed control. The objective of this study was to assess the response of corn hybrids with a wide range of canopy architectures to chemical and mechanical (rotary hoeing) weed control, with an emphasis on quantifying morphology and grain yield responses. Field experiments were conducted in 1997 and 1998 at Ste. Anne de Bellevue, Quebec. Three hybrids were tested: leafy reduced-stature (LRS1 and LRS2), and the conventional hybrid Pioneer 3979 (P3979). Rotary hoeing alone had very little effect, while herbicide application reduced the interference of weeds with growth and grain yield of all hybrids. Hybrid P3979 had more total leaf area than LRS1 and LRS2, but the percentage of leaf area above the ear was much higher for LRS hybrids (70 %) than for P3979 (51 %). Generally, LRS hybrids were much shorter with more leaf area above the ear than P3979, contributing to the large differences in canopy architecture between the LRS hybrids and P3979. However, morphology and grain yield response of hybrids to rotary hoeing and herbicide weed control was not different, indicating that the new hybrids were not more susceptible to damage caused by mechanical weed control than a corn hybrid with a conventional canopy architecture.     

影响青贮玉米品质因素研究进展

青贮玉米是反刍动物的重要粗饲料来源。优质的青贮玉米具有生物学产量高、干物质含量高,粗蛋白含量高、淀粉含量高,纤维素含量低,消化率高等特征。青贮玉米的品质很不稳定,受多种因素影响,影响青贮玉米品质的因素主要包括青贮玉米的品种、生长季的栽培管理措施、玉米的收割时间、青贮措施、添加剂等。本文综述影响青贮玉米品质的主要因素,为青贮玉米生产提供一定参考。