与冬小麦早衰有关的几项生理参数

选取不早衰、轻度早衰及严重早衰三种类型的冬小麦品种,测定其主茎旗叶的叶氮量(单位叶面积含氮量,N/LA)、硝酸还原酶活性(NRA)、氮收获指数(籽粒 N/地上部 N,NHI)、千粒重日增长量及根系活力(RA)。结果表明:随品种早衰程度的不同各生理参数具相似的变化规律,总是不早衰类型的高于严重早衰类型的,轻度早衰的居中。     

与冬小麦籽粒蛋白质有关的几项生理参数

1986—1988年在田间种植7个籽粒蛋白质含量不同的冬小麦品种,于开花、开花后10天、20天和收获各生育期测定茎、叶、穗、粒各部位的氮素含量,旗叶硝酸还原酶活性(NRA),30厘米耕层内的根干重和根活力。结果表明,开花到开花后10天的根干重、根活力、旗叶 NRA 和旗叶叶氮量(N/LA)都继续上升,并维持较高水平;开花后地上部氮同化量     

施氮量对滴灌冬小麦光合特性、产量及氮素利用效率的影响

在田间研究了5 种施氮量N0 (0 kg/hm2)、N1 (90 kg/hm2)、N2 (180 kg/hm2)、N3 (270 kg/hm2)、N4(360 kg/hm2)处理对‘新冬18 号'旗叶光合特性、干物质积累、产量及氮素利用效率的影响。结果表明：拔节期增加施氮量,增加孕穗期旗叶的叶绿素和可溶性蛋白质含量、光合速率、叶面积指数、春季总光合势。孕穗期施氮肥延缓旗叶叶绿素和可溶性蛋白含量、光合速率、叶面积指数的衰减;孕穗后均以N3、N4的旗叶叶绿素和可溶性蛋白质含量、光合速率、叶面积指数、春季总光合势较高,干物质积累量和产量也以N3、N4较高。随施氮量的增加干物质积累量和产量增加,氮肥利用效率降低。在本试验条件下增加施氮量使旗叶叶绿素和可溶性蛋白含量、光合速率、叶面积指数增加及其功能期的延长是‘新冬18号’增产的主要原因。综合考虑施氮量在180~270 kg/hm2范围内,氮肥农学利用效率为6.9 kg/kg,可满足‘新冬18号’产量为8004.85 kg/hm2的需要。     

种植密度对两种穗型冬小麦旗叶氮代谢酶活性及籽粒蛋白质含量的影响

在大田条件下,研究了种植密度对冬小麦多穗型（豫麦49-198）和大穗型（兰考矮早八）品种旗叶氮代谢关键酶活性和籽粒蛋白质含量的影响。结果表明,不同种植密度对旗叶氮代谢酶活性有显著影响。在花后前15 d,两品种旗叶谷氨酰胺合成酶(GS)活性、谷氨酰胺合酶（GOGAT）活性均随各自的种植密度增加而增加;硝酸还原酶（NR）活性则表现为中等密度的较低（兰考矮早八：375株 m^-2;豫麦49-198：150株 m^-2）;花后15 d之后,各酶活性随密度增加的变化趋势不尽相同。在一定范围内,两品种籽粒蛋白质含量随种植密度的增加而增加;表明氮代谢酶活性的提高在一定程度上有利于蛋白质含量的积累。     

氮素水平对小黑麦旗叶叶绿素荧光参数的影响

为了探寻小黑麦适宜的氮素水平,在田间条件下,研究了氮素水平对小黑麦东农5305和东农96026旗叶叶绿素荧光参数的影响。结果表明,小黑麦旗叶最大荧光产量Fm开花后呈M形曲线变化趋势,且随施氮量的增加而有所下降;旗叶最大光化学量子产量Fv/Fm均随施氮量的增加而升高;施氮处理旗叶非光化学淬灭qN低于N0处理;旗叶光化学淬灭qP呈单峰曲线变化,且施氮处理明显高于N0处理。两个小黑麦品种叶绿素荧光参数的变化基本一致。     

水氮耦合对滴灌冬小麦光合特性、产量及水氮利用效率的影响

旨在明确水氮耦合对滴灌下超高产冬小麦光合特性和产量的影响。本研究采用裂区试验,研究了3种灌水量2775 m3/hm2(W1)、3900 m3/hm2(W2)、4350 m3/hm2(W3)水平与3 种施氮量0 kg/hm2(N0)、180 kg/hm2(N1)、270 kg/hm2(N2)水平对‘新冬41 号’旗叶叶绿素和可溶性蛋白质含量、光合速率、水分利用效率以及产量的影响。结果表明,水氮同时增加对花后旗叶叶绿素和可溶性蛋白含量、旗叶光合速率,水分利用效率和产量的提高比仅增加水或氮的作用更大,均以W2N2、W3N2处理花后旗叶叶绿素（分别较W1N0增加44.5%、41.2%）和可溶性蛋白含量（分别较W1N0增加20.8%、16.85%）、光合速率（分别较W1N0增加46.4%、54.5%）、水分利用效率（分别较W1N0 增加31.9%、34.7%）和产量（分别较W1N0 增加19.05%、20.86%）较高,W2N2、W3N2处理的旗叶光合性能大幅度提高是其产量较高的重要原因。综合水氮利用效率,W2N2(3900 m3/hm2、270 kg/hm2)是本试验条件下冬小麦产量近9000.0 kg/hm2的水氮高效运筹模式。     

弱光条件下不同穗型小麦品种旗叶光合特性和抗氧化代谢

在大田试验条件下,比较了大穗穗型小麦品种泰农18和多穗型品种济南17的叶绿素含量、净光合速率(P_n)、可溶性蛋白和总糖含量、抗氧化酶活性及丙二醛(MDA)含量对不同程度弱光响应的差异,为黄淮麦区小麦高产稳产栽培及品种选用提供理论依据。从开花期至成熟期分别对两品种进行25%(S1)、50%(S2)和90%(S3)的弱光处理,以正常光照(S0)为对照。结果表明,S1和S2处理提高了小麦灌浆期内旗叶叶绿素含量和最大光化学效率(F_v/F_m),而S3处理提高了花后0~6 d旗叶叶绿素含量和F_v/F_m,之后显著低于对照;随弱光程度增强旗叶花后实际光化学效率(Φ_PSII)升高,而叶绿素a/b比降低。S2和S3处理显著抑制了旗叶抗氧化酶活性,降低了旗叶P_n、可溶性蛋白和可溶性总糖含量;而S1处理增强了旗叶超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,提高了小麦旗叶P_n、可溶性蛋白和可溶性总糖含量。相同处理条件下,与泰农18相比,济南17的旗叶叶绿素含量较高,光系统II (PSII)活性较强,同时抗氧化酶活性下降较慢,膜脂过氧化程度低,使叶片功能免受破坏,保证了光合作用的进行。75%光照条件下(S1)的小麦抗氧化酶具有较高活性,叶片膜脂化程度低,抗逆性较强,旗叶P_n高值持续期长,有利于光合产物的积累。多穗型品种比大穗型品种更能适应黄淮麦区小麦生育后期光照不足的生产条件。     

低氮诱导小麦灌浆期旗叶衰老与膜脂的关系

小麦产量主要来自于小麦灌浆期旗叶的光合产物, 低氮造成的灌浆期旗叶早衰对小麦产量影响极大。本试验以小麦品种“长旱58”为试验材料, 在大田环境下设置低氮(120 kg hm ^-2)和正常氮(180 kg hm ^-2)处理, 研究低氮诱导的小麦旗叶衰老与膜脂的关系。结果表明, 开花14 d后, 低氮处理小麦旗叶的光合速率、叶绿素含量、旗叶总氮含量均显著降低; 旗叶中膜脂各组分含量均显著下降, DGDG/MGDG的比值升高; 以C18:3、C18:2为代表的不饱和脂肪酸含量显著下降, 以C16:0为代表的饱和脂肪酸含量显著增加, 不饱和双键指数显著降低; 此外类囊体蛋白质堆积密度也显著降低。综合分析认为低氮处理导致小麦灌浆期旗叶早衰, 早衰过程伴随着膜脂降解和组分改变, 降低了膜的流动性和通透性, 导致叶绿素降解, 使光合功能受损。同时, 植物通过调整DGDG/MGDG比例来响应低氮胁迫, 利用DGDG的双层特性来部分弥补其它双层膜脂的降解对膜功能造成的损伤。     

氮肥与精量秸秆还田对冬小麦花后光合特性及产量的影响

为了确定旱地小麦秸秆还田量与氮肥的施用量,在青岛农业大学胶州试验站设不同的秸秆还田量与氮肥处理。研究了精量秸秆还田与施氮量对冬小麦光合特性以及产量的影响。结果表明,与单施N肥处理相比较,适量的秸秆还田能明显提高冬小麦叶绿素SPAD值,延缓旗叶衰老,改善旗叶光合性能,提高小麦千粒质量,但明显降低有效穗数。在同一秸秆还田下高水平氮比低水平氮处理的冬小麦旗叶衰老速度要慢、光合时间更长、产量也明显增多。在施氮225 kg/hm2(N2)下秸秆还田9 000 kg/hm2(J3)比其余处理可明显延缓旗叶衰老、提高光合速率、降低气孔导度、提高蒸腾速率,增加千粒质量。在该地区最具优势的氮肥与秸秆还田量是N2J3处理。     

种植密度对小麦石新828光合特性及产量的调控效应

本试验于大田条件下,研究了种植密度对冬小麦品种石新828在适晚播情况下生育后期旗叶光合特性及产量的调控效应。设置4个密度水平处理;利用CI-340光合测定系统和FMS-2型脉冲调制式荧光仪分别测定了光合特性的相关指标。试验结果表明,种植密度对石新828生育后期光合特性及产量的影响显著;每公顷基本苗330×104处理的旗叶叶绿素(Chl)含量、净光合速率(Pn)、PS II潜在活性(Fv/Fo)及其最大光化学效率(Fv/Fm)均在生育后期始终表现出明显优势,且产量显著高于其他处理;每公顷基本苗210×104和270×104处理由于群体相对较小,表现出对轻度干旱逆境的脆弱性,390×104由于群体相对较大,封闭的小气候影响了个体的发育,最终均导致了产量的降低。小麦石新828在适晚播条件下,适宜种植密度为330×104基本苗/公顷。     

种植密度对夏玉米穗位叶片解剖结构的影响

为了研究种植密度对玉米穗位叶片解剖结构的影响, 以生产上广泛种植的玉米杂交种郑单958和浚单20为材料,采用石蜡制片和超薄切片法对不同种植密度下2个玉米品种穗位叶片和叶绿体的结构进行了观察分析。结果表明, 随着种植密度的增加,2个玉米品种的叶片厚度、叶脉横截面积和叶脉木质部面积减小,上、下表皮的气孔频度减少(郑单958显著,浚单20不显著),叶肉细胞叶绿体的基粒数量减少,维管束鞘细胞叶绿体的数量减少;种植密度在75 000株 hm^-2时产量最高。相关性分析显示,叶脉木质部面积、气孔频度、叶肉细胞叶绿体的基粒数量、叶肉细胞叶绿体的基粒数量与种植密度呈显著负相关,与单穗籽干重、千粒重、穗粒数量呈显著正相关,因而成为玉米生产上的重要结构指标。     

Chromosome Irregularities in Wheat and Triticale Plants Regenerated from Leaf Base Callus

Basal leaf sections of Triticum aestivum L., cv. ‘Chinese Spring’, and XTriticosecale Wittmack cv.‘Welsh’were cultured on Kao's medium with 2 mg/l of 2,4-D. Callus was induced on the leaf sections at frequencies of 64 and 63 %, respectively, and plant-lets regenerated at 18 and 31 %, respectively. Compared to the controls, the regenerated plants showed higher frequencies of univalent chromosomes at meiosis and low frequencies of trivalents, and quadrivalents; indicating that the callus phase had induced low frequencies of chromosome irregularity.     

高产低定额灌溉对冬小麦旗叶衰老的影响

本文在池栽防雨条件下研究了高产低定额灌溉对冬小麦旗叶衰老的影响，结果表明，随灌水次数的减少，小麦旗叶的过氧化物酶活性丙二醛含量增高，可溶性蛋白质，叶绿素含量和超氧物歧化酶活性降低，旗叶光合速率下降，加速膜脂过氧化作用和衰老，但是，灌３水和灌５水的处理之间，上述生理特性和籽粒产量均无显著差异，这是高产效低定额灌溉的生理基础。文中还就不同层次土壤水分状况与衰老的关系及不同灌水方案的灌溉效益进行了分析。     

Delaying senescence of wheat with fungicides has interacting effects with cultivar on grain sulphur concentration but not with sulphur yield or nitrogen:sulphur ratios

Winter wheat was grown in three field experiments, each repeated over two or three seasons, to investigate effects of extending flag leaf life by fungicide application on the concentration, kg ha⁻¹ and mg grain⁻¹ of nitrogen (N) and sulphur (S) as well as N:S ratio and sodium dodecyl sulphate (SDS) sedimentation volume. The experiments involved up to six cultivars and different application rates, timings and frequencies of azoxystrobin and epoxiconazole. For every day the duration to 37% green flag leaf area (m) was extended, N yield was increased by 2.58 kg ha⁻¹, N per grain by 0.00957 mg, S yield by 0.186 kg ha⁻¹ and S per grain by 0.000718 mg. The N:S ratio decreased by 0.0135 per day. There was no evidence that these responses varied with cultivar. In contrast, the relationship between flag leaf life and N or S concentration interacted with cultivar. The N and S concentrations of Shamrock, the cultivar that suffered most from brown rust (Puccinia recondita), increased with the extension of flag leaf life whereas the concentrations of N and S in Malacca, a cultivar more susceptible to Septoria tritici, decreased as flag leaf senescence was delayed. This was because the relationships between m and N and S yields were much better conserved over cultivars than those between m and thousand grain weight (TGW) and grain yield ha⁻¹.     

小麦品种(系)抗叶锈病基因Lr10位点基因型的多样性

小麦抗叶锈病基因Lr10的表达需与其紧密连锁的RGA2基因调控, 按照这2个基因的连锁关系, Lr10基因位点分成H1和H2两个古单倍型。为揭示我国小麦品种中Lr10的遗传多样性, 对189个来自12省的小麦育成品种和58个品系的该基因位点变异进行了鉴定分析。绝大多数供试品种(系)为H2古单倍型, 其频率在育成品种和品系中分别为95.2% (180/189)和96.6% (56/58)。这2种古单倍型可进一步分为9种单倍型亚型, 其中H1-2、H2-4、H2-5、H2-6和H2-7亚型为首次报道。育成品种包含所有单倍型亚型, 以H2-1频率最高(69.3%), H2-3和H2-6频率最低(0.5%); 而在选育品系中仅检测到5种单倍型亚型, 其中H2-1频率最高(27.6%), H1-2频率最低(3.5%)。除H2-1与H2-2型外, 其他亚型与育成地显著相关(P < 0.05)。本研究结果支持Lr10基因位点的古单倍型和单倍型亚型在育种中保持相对稳定的推断, 同时由于在育种过程中持续重组和变异而产生了新的单倍型亚型, 而且重组可以发生在H2和H1两种古单倍型之间。在现代育成品种和品系中, H1古单倍型所占比例已降至5%以下, 应加以保护。     

Frequencies of Vertical Resistances and Virulences in the Rye-Powdery Mildew Pathosystem*

Nine populations of rye (Secale cereale L.; the cultivars ‘Kustro’, ‘Danko’ and ‘Carokurz’. a breeding population PA 14/75 and five Iranian primitive ryes) were tested with three or two pathotypes of powder)’ mildew (Erysiphe graminis DC. f. sp. secalis Marchal) to determine the frequencies of vertical resistances. Similarly, three populations of powder)’ mildew isolated from the above eultivars were tested with two rye pathodemes to estimate the frequencies of vertical virulences. Tests were carried out on leaf segments cultivated in vitro. To explain the pattern of the host-parasite interaction, a model with at least four resistance and virulence genes was required. In the rye populations the genotypes of most plants could be determined unambiguously whereas in the powdery mildew populations no unique classification of one-postule isolates was possible due to the limited number of rye differentials. Both the host and the pathogen populations were polymorphic for resistance and virulence, respectively. In all lye populations except PA 14/75 the resistance frequencies were low. In the mildew populations the virulence frequencies were high and complex races occurred rather frequently. The virulence frequencies were related to the resistance frequencies of the respective host population. Results were compared with mathematical host-parasite models accounting for gene-for-gene interaction and balancing natural selection. Observations agree well with theory.     

山西省不同生态区小麦叶锈菌毒性研究

利用已知抗叶锈病基因的小麦近等基因系 (或单基因系 )作鉴别寄主 ,监测来自山西省 3个不同小麦生态区 11个县 (市 )的 92份叶锈标样。在发现的 2 7个致病类型 (毒性基因组合 )中 ,TRK ,TRT ,PHT ,THT出现频率分别为 19 6% ,9 8% ,6 5 % ,6 5 % ,为优势致病类型。对叶锈菌群体毒性基因频率分析结果表明 ,毒性基因V19,V2 4 ,V38的出现频率较低 ,分别为5 4 % ,16 5 %和 0 ,其对应的抗性基因可视为山西省小麦叶锈菌的有效抗病基因     

A temporal limit to the association between flag leaf life extension by fungicides and wheat yields

Three field experiments, each repeated over two or three seasons, on winter wheat investigated a possible limit to the association between grain yield and flag leaf life, as extended by fungicide application. The experiments involved up to six cultivars and different application rates, timings and frequencies of the strobilurin azoxystrobin and the triazole epoxiconazole. In the 2000/01 and 2001/02 seasons, the relationships between the thermal time to 37% green flag leaf area (m) and yield deviated from linearity. ‘Broken stick’ models were fitted to cultivar × experiment combinations within each season and the limit to the benefit to yield associated with extending flag leaf life was 700 °C days (S.E. = 20.7) and 725 °C days (S.E. = 9.33) after anthesis in 2000/01 and 2001/02, respectively. In 2002/03, the relationship between yield and m did not deviate significantly (P > 0.05) from linearity, but in this latter year the fungicide application failed to increase m past 700 °C days.     

花期玉米(Zea mays)穗三叶叶形结构的遗传效应及配合力分析

为了剖析玉米叶形结构的遗传规律,进而拓宽优良株型自交系的遗传基础。本研究以12份不同叶形结构玉米自交系组配的32份F1杂交种为试材,在2个生态环境下,花期采用加性-显性-母体遗传模型(ADM)对其穗三叶叶长、叶宽、叶夹角、叶向值及叶面积进行遗传效应和配合力分析。结果表明:(1)玉米穗三叶叶长、叶宽及叶向值主要受基因的加性效应调控,其次是显性效应,同时还兼受加性×环境互作效应或母体×环境互作效应等遗传体系的调控,育种改良中宜在早代对其进行选择;叶夹角主要受基因的母体效应调控,其次是加性效应,另外还受加性×环境互作效应及母体×环境互作效应影响,育种中宜选择叶夹角较小的材料作为母本进行改良;叶面积只受基因的显性效应及显性×环境互作效应的调控,其应从较晚世代中进行遗传选择。(2)除父本叶长的一般配合力差异不显著外,父本其余性状的一般配合力和母本全部性状的一般配合力间差异均显著或极显著,且这5个叶形相关性状的全部特殊配合力间差异极显著。(3)从相应自交系各性状的一般配合力相对效应值分析发现,‘锋1999马’和‘锋1913硬’的综合性状表现优良,有利于组配出叶片大小适中及株型紧凑的优良耐密高产F1杂交组合。研究结果表明,玉米穗三叶5个叶形结构的遗传效应不尽相同,相应亲本5个叶形结构的一般配合和特殊配合力间存在明显差异,因此在玉米叶形结构遗传改良上应按照相应性状的遗传特征选择对应改良策略进行改良,并根据综合性状表现优良的亲本有目的地组配杂交组合,提高玉米理想株型育种效率。本研究为进一步剖析玉米叶形结构的遗传机理及玉米理想株型育种提供参考。     

Leafy reduced-stature maize for short-season environments: morphological aspects of inbred lines

Development of maize (Zea mays L.) types that produce leaf area rapidly and finish vegetative development quickly would increase production of maize in mid- to short-season areas. The Leafy (Lfy1) and reduced-stature (rd1) traits each make contributions to this end. However, these two traits have not previously been combined. Our objective was to evaluate the morphological aspects of non-leafy normal-stature (NLNS), leafy reduced-stature (LRS), non-leafy reduced-stature (NLRS), and leafy normal-stature (LNS) maize inbreds. Two traits, Lfy1 and rd1, were incorporated into a series of inbreds, resulting in a range of canopy architectures. Twelve variables were recorded for each of 30 inbreds over three years. The 12 variables were: seed emergence, above-ear leaf number, below-ear leaf number, dead leaf number at tasselling, live leaf number at tasselling, total leaf number, above-ear leaf area, ear leaf length, ear leaf width, ear height, internode length, and plant height. Inbreds containing the Lfy1 trait had more above-ear leaf area, above-ear leaf number, dead leaf number at tasselling, total leaf number and number of live leaves at tasselling than non-leafy inbred lines. Below-ear leaf number was not different among LRS, LNS, and NLNS inbred lines. LRS and NLRS inbred lines were also not different for below-ear leaf number. Plant height, ear height, and ear leaf length and width were higher in normal-stature than reduced-stature plants. The proportion of the seeds which emerged was higher for LRS inbreds than the other trait groups. This revised version was published online in July 2006 with corrections to the Cover Date.