富铁玉米自交系的筛选及配合力研究

以30个玉米自交系以及从中随机抽取的16个自交系按Griffing方法4组配的120个杂交组合为供试材料,在春、夏播中对玉米子粒铁含量、铁含量的配合力进行了分析。结果表明:①供试玉米自交系铁含量变幅为14.98～26.83mg/kg,春、夏播杂交组合铁含量变幅分别为12.39～24.43mg/kg和14.18～27.25mg/kg;②铁含量除受遗传控制外,还明显受播期、基因型与播期互作的影响;③铁含量的GCA(一般配合力)、SCA(特殊配合力)、播期、GCA与播期互作、SCA与播期互作均达到显著或极显著水平;④多数铁含量SCA效应值较高的组合,至少有一个亲本的GCA效应值较高,但也有部分铁含量SCA效应值较高的组合,其双亲的GCA效应值却较低,表明在选育杂交组合时,应在选择铁性状GCA较高亲本基础上,通过广泛测交加强SCA选择;⑤亲本铁含量的表型值与GCA效应呈极显著正相关,相关系数r=0.70,在一定程度上可通过亲本铁含量表型值的水平来预测亲本GCA效应值的高低。     

关于高赖氨酸玉米选育方法的探讨

利用3个普通玉米自交系和6个高赖氨酸玉米自交系进行双列杂交,分析了不同类型杂交组合的产量、赖氨酸含量和其它几个子粒性状的表现,并且通过灰色关联度法综合评价了各组合的优劣,以探讨用普通玉米和高赖氨酸玉米自交系组配单交种选育高赖氨酸玉米的可行性。从平均值看,普×高组合在产量、粒重、容重和收获时子粒含水量方面均优于高×高组合,普×高组合的子粒赖氨酸含量低于高×高组合,但两者的单位面积赖氨酸产量相近。灰色关联度法评价出的前10个组合中有7个是普×高组合,3个是高×高组合,并且第1、2、4、5、6位组合都是普×高组合。因此,用普通玉米自交系作母本与高赖氨酸玉米自交系组配杂交种是值得深入探讨的一种选育高赖氨酸玉米杂交种的有效途径。     

普通玉米和O2玉米自交系间杂交种子粒赖氨酸含量及子粒性状的分析

用普通玉米自交系和O2玉米自交系进行双列杂交,对普通玉米×O2玉米(普×O2)、普通玉米×普通玉米(普×普)和O2玉米×O2玉米(O2×O2)三种类型杂交组合F1的子粒赖氨酸含量、产量、赖氨酸产量、容重、收获时子粒含水量进行了比较分析。结果表明:普×O2组合的赖氨酸含量介于普×普和O2×O2之间,但变化幅度较大;产量和粒重最高,容重和收获时子粒含水量介于两者之间偏近于普×普,赖氨酸产量和O2×O2接近。认为以普通玉米与O2玉米自交系组配杂交种是一种值得探讨的高赖氨酸玉米选育方法。     

高油与普通玉米自交系子粒品质性状的配合力分析

以8个ALEXHO高油玉米自交系为父本,21个普通玉米自交系为母本,采用NCⅡ遗传设计组配168个F1组合为供试材料,对其子粒油分、蛋白质和淀粉含量进行配合力分析。结果表明：除高油玉米自交系淀粉含量的一般配合力(GCA)方差以及淀粉含量的特殊配合力(SCA)方差不显著外,其余性状的GCA和SCA方差均存在极显著差异。GY220、GY246A、GY798A、P138、许178、8622油分含量的GCA较高,GY1007、GY237A、8085泰、沈137、改3、鲁原92蛋白质含量的GCA较高。P138×GY798A、87-1×GY246A、许178×GY798A和87-1×GY220组合油分含量高,鲁原92×GY1007蛋白质含量较高。     

华安县耕地土壤氮磷钾含量及丰缺状况研究

采用野外调查与室内分析相结合的方法研究华安县不同耕地土壤类型土壤氮磷钾含量及丰缺状况。结果表明：(1)土壤有机质含量为(23.74±5.06)g/kg,总体上处于较丰富水平。(2)全氮含量为(1.20±0.17)g/kg,总体处于较高水平;碱解氮为(46.57±11.19)mg/kg,属于缺乏水平。(3)全磷量(0.72±0.17)mg/kg,总体处于中等水平;有效磷含量(22.48±14.23)mg/kg,总体处于中等水平,且不同土壤类型之间有效磷差异明显。(4)全钾量(15.12±7.06)g/kg,     

不同玉米品种子粒植酸磷及其他形态磷含量的相关性研究

以50个自交系和24个杂交种为材料,测定其总磷、植酸磷、无机磷含量,分析不同基因型玉米子粒中植酸磷及其他形态磷含量的差异性和相关性。结果表明：不同自交系和杂交种间3种磷形态的含量均存在显著差异,植酸磷与总磷间呈正相关,与无机磷间呈弱度正相关。在低植酸玉米选育时,应该同时采用植酸磷和无机磷两个指标作为选择标准。自交系丹黄02是选育较低植酸磷、高无机磷含量杂交种的优良亲本材料。     

本试验结果表明:从吉林省农业科学院引进的玉米杂交种四单19在西藏林芝和拉萨均可种植,其经济产量和生物产量均较高;在西藏林芝首次进行四单19(吉444×Mo17)玉米杂交种繁育制种试验,初步取得了成功,在933 m2土地上生产出95.2 kg杂交种和74.2 kg父本自交系。

本试验结果表明:从吉林省农业科学院引进的玉米杂交种四单19在西藏林芝和拉萨均可种植,其经济产量和生物产量均较高;在西藏林芝首次进行四单19(吉444×Mo17)玉米杂交种繁育制种试验,初步取得了成功,在933 m²土地上生产出95.2 kg杂交种和74.2 kg父本自交系。     

普通玉米单交种与高油玉米杂交当代子粒化学成分的遗传分析

试验以吉林省主推的普通玉米单交种为母本,以高油玉米为父本进行人工杂交,研究双亲对杂交当代子粒的脂肪、蛋白质和淀粉含量的影响.结果表明:①母本对杂交当代子粒脂肪含量的影响大于父本,杂交当代子粒的脂肪含量与其双亲的关系是:普通玉米单交种×高油玉米自交系杂交当代子粒的脂肪含量=0.60P₁+0.40P₂;普通玉米单交种×高油玉米单交种杂交当代子粒的脂肪含量=0.65P₁+0.35P₂;普通玉米单交种×高油玉米群体的杂交当代子     

春玉米子粒灌浆期可溶性糖含量变化与淀粉积累关系的研究

以田间种植的高淀粉(郑单19)、高油(通油1号)和普通型(吉单209)春玉米为材料,探讨不同类型玉米杂交种之间可溶性糖含量变化与淀粉积累的关系。从授粉后第7天开始,每隔7d选取果穗测定子粒的蔗糖、葡萄糖、果糖和淀粉含量。郑单19的淀粉含量在子粒灌浆的前期和后期都高于通油1号和吉单209;郑单19的蔗糖含量在前期较低,在后期较高,吉单209和通油1号的蔗糖含量变化趋势相似;在前期郑单19的葡萄糖含量高于其它两个杂交种,果糖含量显著高于蔗糖和葡萄糖含量;在前期和中期郑单19的果糖含量低于其它两个杂交种。结果表明,在子粒灌浆前期果糖的转化是淀粉积累的主要限制因素。     

热带、亚热带玉米种质在北方早熟春玉米育种中的利用研究

试验选用地方常用自交系甸骨11A、红玉米、长3、Mo17(未改良自交系)和导入热带玉米种质选育的8份自交系(改良自交系),每份改良自交系分别选定2个测验种,配制16个杂交种(改良杂交种),未改良系与选定2个测验种组配的杂交种(未改良杂交种)作为改良杂交种的相邻对照,对比法设计。改良自交系和未改良自交系、改良杂交种和未改良杂交种的性状观测值作为一对数据,按成对资料统计方法分析,t测验。结果表明:甸骨11A导入Suwan1、5-56的改良自交系与红玉米杂种优势较高,红玉米导入Suwan1、EVT5的改良自交系与甸骨11A杂种优势较高,长3导入Suwan1、墨黄9的改良自交系与海014的杂种优势较高。改良自交系主要性状变化表现为生育时期延后、单株产量增加。未改良自交系熟期越早,改良自交系及改良杂交种生育时期延后时间越长,改良自交系单株产量增加幅度越大。改良自交系及其改良杂交种的玉米大斑病、茎腐病的抗性有了较大提高。     

杂交水稻不同器官重金属铅浓度与累积量

以生长于盆钵中的两系杂交稻和三系杂交稻共6个组合为试验材料,设置土壤铅(Pb)浓度为500mg/kg和不加Pb土壤(对照)两个处理,测定水稻植株不同器官Pb的浓度和累积量。结果表明,Pb处理降低了两优培九、103S/郑粳2号、丰优香占和汕优63的产量,主要是每穗粒数减少,对其余组合的产量无显著影响;不同基因型水稻植株对Pb吸收与积累存在差异,以103S/郑粳2号和两优培九累积量最多,K优818累积量最少;水稻植株不同器官Pb的浓度和累积量的大小顺序为根>茎鞘>叶片。籽粒不同部位Pb的浓度大小顺序为糠层>颖壳>精米,精米中Pb累积量仅为谷粒的25%左右,精米中Pb的浓度以103S/郑粳2号最高,K优818最低;在抽穗期和成熟期,同一器官Pb浓度与累积量呈显著或极显著正相关,但不同器官之间的相关不显著。对不同杂交稻组合植株中Pb浓度和累积量差异的原因进行了讨论。     

Ecophysiological traits in maize hybrids and their parental inbred lines: Phenotyping of responses to contrasting nitrogen supply levels

Maize (Zea mays L.) breeding based primarily on final grain yield has been successful in improving this trait since the introduction of hybrids. Contrarily, understanding of the variation in ecophysiological processes responsible of this improvement is limited, especially between parental inbred lines and their hybrids. This limitation may hinder future progress in genetic gain, especially in environments where heritability estimation is reduced because grain yield is severely affected by abiotic stresses. The objective of this study was to analyze the genotypic variation between inbred lines and derived hybrids in the physiological determinants of maize grain yield at the crop level, and how differences among hybrids and parental inbreds may effect contrasting responses to N stress. Special emphasis was given to biomass production and partitioning during the critical period for kernel number determination. Phenotyping included the evaluation of 26 morpho-physiological attributes for 6 maize inbred lines and 12 derived hybrids, cropped in the field at contrasting N supply levels (N₀: no N added; N₄₀₀: 400 kg N ha⁻¹ applied as urea) during three growing seasons. Tested genotypes differed in the response to reduce N supply for most measured traits. Grain yield was always larger for hybrids than for inbreds, but N deficiency affected the former more than the latter (average reduction in grain yield of 40% for hybrids and of 24% for inbreds). We also found (i) a common pattern across genotypes and N levels for the response of kernel number per plant to plant growth rate during the critical period, (ii) a reduced apical ear reproductive capacity (i.e., kernel set per unit of ear growth rate) of inbreds as compared to hybrids, (iii) similar RUE during the critical period and N absorption at maturity at low N levels for both groups of genotypes, but enhanced RUE and N absorption of hybrids at high N supply levels, and (iv) an improved N utilization efficiency of hybrids across all levels of N supply. Results are indicative of a more efficient use of absorbed N by hybrids than by parental inbreds. Larger grain yield of hybrids than of inbreds at N₀ was associated to (i) enhanced dry matter accumulation due to improved light interception during the life cycle and (ii) enhanced biomass partitioning to the grain.     

Higher crop performance of rice hybrids than of elite inbreds in the tropics: 2. Does sink regulation,rather than sink size,play a major role?

Higher harvest index, widely reported as a main trait supporting major improvements in rice yield potential, also supports the higher performance of hybrids over inbreds. Although higher sink size is generally claimed for being the driver of higher grain filling in hybrid rice, it is relevant to question whether efficient sink regulation, that is timing and magnitude of the successive sink activities over crop growth from early stage, plays a role in supporting higher harvest index and is a key feature ensuring higher performance of hybrid rice. The partitioning coefficient (PC), as the increase in dry matter of one single organ over that of shoot, was calculated over short and successive periods to quantify the dynamics of dry matter partitioning. Four hybrid and four inbred genotypes of similar crop duration were grown under the same cropping management on the IRRI farm during a wet and a dry seasons. While PC to blade and sheath was similar for both plant types in both seasons at the early stage, PC to culm of hybrids was higher than that of inbreds, and PC to blade was lower, in the late vegetative and early reproductive phases. During the late reproductive phase, PC to panicle of hybrids was higher than that of inbreds, and PC to culm was lower whereas culm elongation was similar for both plant types. During grain filling, PC to culm was significantly more negative with hybrids which indicated stronger remobilization with hybrids. Specific culm length before anthesis, as low as 40 cm g⁻¹, accounted for storage ability, and at maturity, as high as 130 cm g⁻¹, for remobilization ability. Sink strength index, as a better indicator of dry matter partitioning efficiency than harvest index, and unfilled grain size, as an indicator of assimilate wastage, were suggested as key indices to account for the better sink regulation in hybrid rice and to improve screening protocols for increasing yield potential and tolerance to lodging.     

Nutritional evaluation of spent grains from sorghum malts and maize grit

Potential use of the high protein by-product of beer production from 77% sorghum malt and 23% maize grit was investigated. Red sorghum spent grains (RSSG) and white sorghum spent grains (WSSG) contained 23.4 and 19.3% crude protein (CP), 54 and 43% dietary fiber (NDF), 1.44 and 0.78% ash, 4.5 and 3.2% hexane extract and tannin content of 7.5 and 1.0 mg/g catechin equivalent respectively. Magnesium was the most abundant mineral in both RSSG and WSSG — 185 and 140 mg/kg, respectively. Calcium, zinc, iron and copper were generally low. Both samples contained cadmium 1.12 (WSSG), 1.19 (RSSG) and lead at 1.38 mg/kg. Lysine was the limiting amino acid (chemical score 0.55) in both samples. Other essential amino acids were adequate or surplus. Stearic acid was the predominant fatty acid with varying levels of lauric, myristic, palmitic, and oleic acids in both samples. Feed intake and weight gain were highest in rats fed 26.3% WSSG (contributing 50% of the diet protein) but protein efficiency ratio (PER) and net protein retention (NPR) were highest in diets where spent grains contributed just 25% of the diet protein. True digestibility of diets decreased as dietary fiber content increased such that animals on diets containing 100% spent grain protein (above 20% NDF) lost weight.     

籼爪交和粳爪交杂种F1代性状间关系的研究

对229个籼爪交组合、98个粳爪交组合的农艺性状进行了相关分析,对籼爪交和粳爪交组合的单株粒重、结实率进行了通径分析,对籼爪交组合农艺性状和品质性状进行了典型相关分析.籼爪交和粳爪交组合间性状相关性表现不同,独立性强的性状籼爪交组合中为谷长、粳爪交组合中为谷宽,其余性状间表现出复杂的相关关系.籼爪交和粳爪交组合均表现每穗实粒数和单株穗数对单株粒重的直接正效应大;每穗实粒数多、单株穗数多且生育期短或适中是提高籼爪交组合单株粒重的选育方向;粳爪交杂种提高单株产量的育种方向是选育每穗实粒数多并且单株穗数也多的组合,同时要兼顾增加每穗总粒数.每穗实粒数对籼爪交杂种结实率的直接正效应大,籼爪交杂种结实率的提高主要依赖每穗实粒数的增加,而其它性状的选择和改良作用不大.提高粳爪交杂种结实率可从3个方面入手,即选育每穗实粒数较多、每穗总粒数较多、且千粒重较大的组合,但主要是提高每穗实粒数.农艺性状和品质性状间存在典型相关.     

玉米不同产量水平下穗粒结构分析

利用相关及通径分析的方法,对河南省18年夏玉米区试255个杂交种的产量和穗部性状进行分析.认为7500kg/hm²以下的杂交种,起主要作用的依次是千粒重、穗长、行粒数、出籽率、穗粗、穗行数.在选择7500kg/hm²以上的杂交种时,除了要稳定、提高穗粗、穗行数外,必须重点对千粒重、穗长进行正向直接选择,其次是行粒数和出籽率;对秃尖、轴粗进行负向直接选择;同时要协调好各性状间遗传相关关系。     

Localisation of iron in wheat grain using high resolution secondary ion mass spectrometry

Insufficient iron (Fe) is one of the most prevalent micronutrient deficiencies in humans, with billions of people affected. Cereal grains are an important source of Fe for humans but the bioavailability of Fe in cereals is generally low. Information regarding the cellular and sub-cellular localisation of Fe in wheat grain will aid optimising nutrient delivery for human health. In this study high resolution secondary ion mass spectrometry (NanoSIMS) was used to map the distribution of Fe in the aleurone layer and in the endosperm of immature wheat grain. Iron was shown to be localised strongly in the phytin globoids in the aleurone cells and to a lesser extent in the cytoplasm around the starch granules in the endosperm.     

铜、镉胁迫对冬小麦籽粒淀粉含量和糊化特性影响的初步研究

为给小麦优质安全生产提供理论依据，以中筋型冬小麦品种豫麦70为供试材料．于2004～2005年度在盆栽试验条件下，设置Cu、Cd两种重金属元素各三个浓度水平，即Cu1（100mg／kg）、Cu2（200mg／kg）、Cu3（300mg／kg）和Cd1（10mg／kg）、Cd2（50mg／kg）、Cd3（100mg／kg），共6个处理，以不施重金属元素处理为对照，研究了Cu、Cd胁迫对冬小麦籽粒淀粉含量及其糊化特性的影响。结果表明，籽粒淀粉含量随Cu、Cd浓度的增加而降低，与对照相比，Cu处理最大降幅为9．58个百分点，Cd处理最大降幅为11．45个百分点。Cu处理对籽粒淀粉糊化特性的影响随浓度的增大而增加，其中，对峰值粘度、低谷粘度、最后粘度和反弹值的影响较大，对稀懈值的影响较小；Cd处理对淀粉糊化特性的影响表现为随浓度的增大．各性状值先增加后降低的变化特点，且以Cd。处理的影响最大。Cu、Cd胁迫下，籽粒产量和籽粒蛋白质产量随Cu、Cd浓度的增加而急剧下降；籽粒蛋白质含量也随浓度的增高而降低，但处理间差异均未达显著水平。这些结果表明，在本试验条件下，过量施用重金属Cu、Cd对小麦植株产生了明显的胁迫危害，致使小麦籽粒淀粉含量下降，并造成严重减产。     

氮肥运筹对不同茬口强筋小麦籽粒产量和品质的影响

为了探讨不同茬口下施氮对强筋小麦籽粒产量和品质的最佳效应,以强筋小麦品种烟农19号为材料,研究了施氮量和追氮时期对不同茬口小麦籽粒产量及品质的影响。结果表明,施氮量和追氮时期对不同茬口下强筋小麦的籽粒产量和品质均有显著的影响。在0～240kg／ha施氮量范围内烟农19号单位面积穗数、每穗粒数和产量随施氮量的增加而显著提高,且旱茬麦产量极显著高于稻茬麦,主要是提高了每穗粒数和千粒重。小麦籽粒蛋白质和面筋含量、沉淀值均随施氮量的增加而显著增加,旱茬麦的品质显著优于稻茬麦。在两种茬口下,烟农19号籽粒产量、蛋白质产量与施氮量均成二次曲线关系,稻茬麦在施氮量为251．26～280．24kg／ha、旱茬麦在施氮量为281．03～303．02kg／ha范围内籽粒产量和蛋白质产量可达到同步提高。拔节期和孕穗期追施氮肥可有效提高单位面积穗数、每穗粒数和产量,且籽粒蛋白质、湿面筋含量和沉淀值显著提高。本试验条件下,旱茬麦在拔节期至孕穗期、稻茬麦在孕穗期追施氮肥可同步提高强筋小麦籽粒产量和品质.     

杂交小麦组织氮积累及含量的杂种优势

选用6个杂交小麦及其7个亲本材料在不同施氮条件下，研究了小麦在不同生育时期不同组织器官的氮积累和含量的杂种优势及其与籽粒产量、籽粒氮产量和含量的关系。结果表明．在施氮条件下，组织氮积累和含量在多数取样期表现正向杂种优势，杂交种CH51和APOLLO尤为如此。6个杂交小麦籽粒产量杂种优势的平均值为9．6％，MERCURY的杂种优势最高，达到了22．72％。在施N条件下，APOLLO的籽粒氮含量杂种优势为8．1％，在6个杂种小麦中最高。在多数取样期，植株、茎秆氮积累和含量的杂种优势与籽粒氮产量和含量杂种优势存在中度偏高的正相关关系，与籽粒产量的杂种优势无显著相关关系，因此，在杂交小麦选育中，在保持较高的籽粒产量优势下，选择高的组织氮积累和含量优势，很有可能提高籽粒氮含量的杂种优势。