脱水对万寿竹种子发芽及部分抗逆生理指标的影响

[目的]探究万寿竹种子脱水过程中,发芽及部分抗逆生理指标的变化情况,为万寿竹种子贮藏及采收提供理论依据.[方法]利用室温硅胶干燥法获得45.90％、40.50％、38.07％、33.08％、27.26％、16.67％、14.63％7个含水量梯度的种子,以未干燥的种子(49.12％)为空白对照,分别测定各个含水量梯度种子的生活力、发芽率、电导率、CAT、SOD、POD、AsA-POD活性、MDA、可溶性蛋白质含量.[结果]种子含水量保持在33.08％以上时,能保持较高的生活力、发芽率,当含水量下降到33.08％以下时,种子发芽率和生活力开始显著下降.[结论]万寿竹种子不耐脱水,属于顽拗性种子,贮藏时含水量应保持在33.08％以上.     

繁种地对甜荞麦种子质量的影响

为研究繁种地对甜荞麦种子质量的影响,本实验以11份甜芥品种为材料,分别种植于青海湟中、西藏山南、内蒙古呼和浩特和云南安宁,研究繁种地对种子千粒重、净度、穗萌芽率、生活力和活力的影响。研究表明,繁种地对各栽培甜荞的种子质量均有一定的影响。除了采收于青海的蒙0530,其他种子的千粒重均大于20g;所有种子的净度均在99%以上;所有品种在云南存在无穗萌发现象,种植于青海的甜荞穗萌发最为严重;采收自西藏的荞杂-2、荞杂-1、综甜荞2号、定甜荞3号、信农1号、蒙0208和蒙0530发芽率均低于85%,失去种用价值;采收自内蒙古和云南的种子幼苗干重较优异。综合分析,云南安宁和内蒙古呼和浩特采收种子的质量较高,可作为甜荞优良品种的繁种地,生产优质种子。     

Effectiveness of pre- and post-veraison calcium applications to control decay and maintain table grape fruit quality during storage

A two year research was carried out on a table grape vineyard, cv. Italia, to evaluate the effectiveness of pre- and post-veraison calcium applications for controlling postharvest table grape rots and maintaining high fruit quality during cold storage. Two calcium application timings (from fruit set to veraison and from veraison to harvest) were compared to an untreated control. Clusters were sprayed with calcium chloride as Ca EDTA 44%. After each calcium application, bunch samples were collected and Ca²⁺ concentration was measured in berry compartments (skin, flesh and seeds). The main mechanical and chemical characteristics were measured on bunch samples at harvesting and during storage. In addition, the incidence of Botrytis cinerea rots, computed as McKinney index, was evaluated in field on natural inoculum and after harvesting on bunches artificially inoculated and maintained at room temperature. The highest Ca²⁺ concentrations were detected in skin tissues and after pre-veraison applications. Calcium accumulation in skin and flesh tissues stopped after veraison, whereas it continued up to ripening in seeds since the axial flow, differently from the peripheral, remains functional. In both years, calcium applications to bunches were effective both in maintaining postharvest fruit quality, as shown by flesh firmness and berry breaking force, and in reducing B. cinerea rots during storage. The applications were particularly efficacious if carried out between fruit set and veraison when stomata are functional and the re-translocation of calcium not directly absorbed by the bunches may occur via xylem transport.     

黄土高原旱作玉米籽粒水分与机械粒收质量的关系

玉米机械粒收是全程机械化的关键, 但存在着籽粒破碎、果穗和落粒损失严重等备受关注的问题。开展机械粒收质量及其影响因素研究, 对推进旱作玉米机械粒收技术应用具有重要意义。本研究选择国内玉米主栽品种33个, 于2016-2017年在甘肃泾川同一地块上用福田雷沃谷神收割机械粒收, 分析籽粒水分与机械粒收质量指标的关系。结果表明, 基因型差异是造成玉米机械粒收质量不同的主要原因, 两年收获时平均籽粒水分26.05%, 破碎率7.47%, 产量损失率3.25%, 落穗损失率2.58%, 杂质率1.04%; 籽粒水分(X)与破碎率(Y₁)、产量损失率(Y₂)显著正相关, 并且存在Y₁ = 0.027X ²-0.987X+14.06 (R ² = 0.373 ^**, n = 51), Y₂ = 0.052X ²-2.223X+24.86 (R ² = 0.418 ^**, n = 51)的变化关系, 籽粒水分依次下降到18.3%、21.4%时, 对应的破碎率(5.1%)、产量损失率(1.1%)最低, 即在一定含水率范围内随着籽粒水分的增加破碎率、产量损失率升高, 机械粒收的籽粒适宜水分为18%~22%, 破碎率可控制在5.0%~5.5%的范围内; 籽粒水分对落穗损失的影响大于落粒损失, 随着籽粒水分增加落穗损失率增加的幅度明显高于落粒损失率的升高; 各因素对玉米机械粒收产量损失的影响为: 落穗损失率(0.924)>籽粒水分(0.048)>破碎率(0.043), 因而籽粒水分高和落穗损失量大是影响黄土高原旱作玉米机械粒收质量的主要因素。     

不同采果期多花黄精的果实成熟度及种子调制研究

[目的]研究多花黄精果实最佳采收期和种子调制方法.[方法]9月1日-11月1日每15d采收1次多花黄精果实,分析果实的颜色比例、百果重、百果体积、果实的纵径、横径和果实硬度;不同采收期的种子不同调制处理,分析种子千粒重、发霉率、生活力、发芽率、发芽势.[结果]绿果和半墨绿果的果实成熟度低,墨绿果的果实成熟度高;10月1日未见绿果和半墨绿果,黑软果出现;11月1日干枯果出现.9月1日、9月15日、10月1日采收的绿果分别发酵20,19,16d和墨绿果分别发酵19,16,4d种子质量最好;10月15日和11月1日采收的果实直接搓洗的种子质量较好.[结论]在种子生产中应该采摘墨绿果、黑软果和干枯果.10月1日至10月15日是贵州六枝地区的多花黄精果实最佳采收日期,此时绿果和墨绿果分别发酵16d和阴干处理的种子质量最好.     

常规库存条件下春小麦种子发芽能力随贮藏年限的变化研究

分析常规库存条件下,贮藏春小麦种子发芽能力变化特点,为春小麦种子长时间贮藏提供实践依据。试验用15份春小麦材料,连续测定了2009—2017年间的发芽势和发芽率,并对种子的发芽势和发芽率随贮藏年限的变化进行分析。研究表明,小麦种子在常规库存条件下,发芽势和发芽率随贮藏年限的增加逐年降低,发芽势的年降速率快于发芽率的年降速率;小麦品种间发芽势和发芽率随贮藏年限的变化存在差异性;同一小麦品种,会受到品种和收获环境互作效应的影响,在不同环境下种植与收获,发芽势和发芽率随贮藏年限的变化会有不同。由此认为在检测库存小麦种子发芽力时,应按照不同贮藏年限、不同品种、同一品种不同来源等,对种子分批逐个检测,不能随意替代。     

叶底红种子发芽特性研究

为明确不同条件下叶底红种子的发芽特性,通过发芽试验,考察了种子发芽过程和不同温度、光照、采收期、种子贮藏时间等因素处理条件对发芽的影响。结果表明：叶底红种子属于无胚乳种子,种子发芽为子叶出土型。在温度10~25℃范围内,温度越高,种子发芽速度越快,25℃下的发芽时间为11天,30℃以上处于休眠状态;秋季采收的种子的发芽质量最好,幼苗长势也最好;种子发芽需要一定光照,播种以不覆土为好;贮藏期对发芽速度影响不显著,但对发芽率有极显著的影响,在贮藏30天内,发芽率下降5.7%,贮藏240天的种子只有12.7%的发芽率。     

甘蓝型油菜隐性核不育系ZWAB临保三交种与单交种的比较

利用甘蓝型油菜隐性核不育系ZWAB及临保系和恢复系分别配制了临保三交种、单交种进行组合的杂种优势比较,结果表明:临保三交种在抗性方面优于单交种,在经济性状及产量上与单交种相当。临保三交种完全可以替代单交种,从而节省了两系制种过程中初花期拔除50%可育株的环节,降低了劳动强度和成本,提高了制种产量和种子纯度。     

玉米宜粒收品种的选育及种质创新策略

进入21世纪以来,玉米生产方式逐步由人工收获过渡到机械穗收,再到机械粒收,生产上迫切需要适宜粒收玉米品种,因此选育推广宜粒收玉米品种,完成新一代品种更新换代对于保障粮食增产增效、提高玉米生产竞争力和最终实现玉米生产全程机械化具有重要意义。本研究根据前人研究结果总结了宜粒收品种农艺性状及遗传特性,明确了宜粒收玉米品种的关键指标:(1)收获时籽粒含水量低;(2)早熟耐密;(3)抗倒伏(折)和抗病(穗粒腐和茎腐病)。结合育种实践,提出了围绕技术创新、种质创新、杂种优势模式创新选育出宜机械粒收玉米新品种育种策略,期望在育种实践中有所帮助。     

水稻不育系"龙特浦A"简易穗选提纯技术

通过对水稻不育系“龙特浦A”自交结实规律的分析，提出了简易穗选提纯法，即在不育系“特A”原种繁育圃收割前，穗选性状典型、结实率高的“特A”、“特B”主穗，分别进行单晒单藏，作为原原种，供原种繁育田使用。本方法有效地提高了不育系原原种和原种的纯度，简化了提纯繁育程序，且原种用于制种后所收获的杂种一代种子纯度达到国家标准。     

耐密抗逆高产宜机收玉米新品种‘瑞普909’的选育研究

为适应当前玉米密植与机械化快速发展的需求,利用国外优异玉米种质材料组配基础群体,采用高密度大群体,定向接种鉴定等方法,以选育的抗病优良自交系‘RP86’为母本,‘RP06’作父本,杂交组配育成耐密抗逆高产宜机收玉米新品种‘瑞普909’。区试平均产量为12589.5 kg/hm ²,比对照品种增产7.1%,试验点111个,增产点占93%;生产试验产量为12601.5 kg/hm ²,比对照品种增产7.7%,试验点54个,增产点占95%。区域和生产试验平均倒伏（倒折）率1.6%,抗大斑病、茎腐病和穗腐病。籽粒粗淀粉含量75.24%。研究表明,该品种高产稳产、抗病抗倒、品质优良、适应性广、耐密植、宜机收。2017年通过山西省审定,2018年通过陕西、内蒙古和国家审定。适宜在东华北、西北春播中晚熟区和山西南部等黄淮海夏玉米区推广种植。     

Seed storage protein composition of Hellenic bread wheat cultivars

The allelic diversity in seed storage proteins of 25 bread wheat cultivars grown in Hellas was investigated. In total, 15–20 seeds per cultivar were used for the determination of the alleles present at the loci coding for high‐molecular‐weight glutenin subunits and gliadins. For this purpose, acid polyacrylamide gel electrophoresis for gliadins and SDS‐electrophoresis for glutenins were employed. Analysis of the electrophoretic patterns revealed that intravarietal selections obtained from the cultivar ‘Nestos’, together with the cultivar ‘Eurydice’ which was selected from the cultivar ‘Nestos’, were identical to their original cultivar and to the cultivar ‘Dodoni’. The cultivars ‘Penios’, ‘Siette Cerros E’, ‘Gorgona’ and ‘Louros’, although recorded to differ in descent, were found to be identical at all the loci examined. Finally, it was revealed that four of the Hellenic cultivars carry the wheat‐rye 1BL/1RS translocation. These data could be beneficial for a better understanding of the existing differences in quality and stress‐resistance between the cultivars examined.     

Inheritance of resistance to pendimethalin herbicide induced stem damage in soybean

Selective herbicides are valuable weed control tools; however, selectivity is not always complete, resulting in crop damage. Stem breakage, lodging, and enlarged hypocotyls (brittle bean syndrome) limit yields of soybean [Glycine max (L.) Merr.] genotypes treated with pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine]. Developing genotypes with resistance to pendimethalin injury would eliminate or reduce this problem. Genetic studies were conducted to determine the inheritance of resistance to pendimethalin induced stem damage. The F_2:3 progeny of crosses involving resistant ('Asgrow A4715' and 'Flyer') and susceptible (`Essex' and K87-7-95) genotypes were screened in a greenhouse. Each genotype was treated with 1.68 kg ha^-1 pendimethalin preemergence and irrigated as needed. Plants were scored at V4 for stem breakage. Progeny distributions indicated that resistance to brittle bean syndrome damage behaved as a quantitative trait. Dominance for stem breakage was expressed in the population of A4715 × Essex. Flyer was more sensitive to herbicide damage than Asgrow A4715 because it has fewer genes for resistance or different alleles. The F_2:3 variance component heritability estimates ranged from 0.19 to 0.52. Gain from selection for resistance to pendimethalin injury is possible, and resistant progeny can be recovered from segregating populations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Stratification and Bearing Capacity Prediction Method Based on BP Neural Network for Foundation in Huaibei Plain

According to the features of stratification and obvious inhomogeneity in geological soil in Huaibei plain, BP neural network prediction method for stratification and bearing capacity calculation of multiple cross-bedded foundation was proposed. By comparing the results of drill sampling, static cone penetration tests and screw plate tests, plate loading tests, penetration resistance ps value was found as an evaluation index for stratification and bearing capacity prediction of cross-bedded foundation. Moreover, gradient descent algorithm and conjugate gradient algorithm BP neural network models were obtained, and the calculation results of the two algorithms were comparatively analyzed. The results show that penetration resistance value can be taken as an evaluation index for stratification and bearing capacity prediction of cross-bedded foundation in Huaibei plain. Gradient descent algorithm and conjugate gradient algorithm BP neural network models have good results for soil identification and bearing capacity determination, which can meet the accuracy requirements of actual engineering. However, the computational efficiency of gradient descent algorithm is significantly lower than that of conjugate gradient algorithm.     

玉米矮花叶病的抗性遗传分析

以玉米自交系X178和B73杂交培育的183个重组自交系为试验材料,采用人工接种的方法,在苗期、拔节期、抽雄期和成株期进行了玉米矮花叶病的抗性鉴定.结果表明,183份重组自交系之间对玉米矮花叶病的抗性存在着较大的差异,在抽雄期和成株期各有3个高抗的超亲分离;苗期和拔节期的病株率均呈现正态分布,抽雄期和成株期则表现为感病家系较多的偏态分布,且家系病株率的变异系数随生长发育变得越来越小,但抗性遗传力则越来越大.说明对玉米矮花叶病的抗性鉴定在成株期较准,苗期受环境影响较大;成株期的抗性由2～3对主基因控制,同时存在多基因修饰或互作;抗性基因之间以加性效应为主.     

Fine mapping of the <Emphasis Type="Italic">R</Emphasis><Subscript><Emphasis Type="Italic">SC14Q</Emphasis></Subscript> locus for resistance to soybean mosaic virus in soybean

In maize hybrid seed production, some hybrid seed in the field must be harvested before reaching physiological maturity because of the potential damage from early fall frosts. However, early harvesting can result in poor quality and low vigor of seeds. To elucidate the genetic basis of seed vigor at different stages of maturity, the seeds of a set of recombinant inbred line (RIL) populations at three different stages of maturity (32, 40, and 45 days after pollination; DAP), were used to evaluate the performance of four traits for seed vigor in the field. A genetic linkage map was constructed using 217 SSR makers covering 2438.2 cM with an average interval of 11.2 cM. The results showed that there were significant positive relationships among the four traits of seed vigor at all three sampling times, and all showed quantitative changes according to the degree of maturity of the seeds. However, the four traits of seed vigor were not significantly related to the 100-kernel weight. In total, we detected 16 different QTL for the four measured traits of seed vigor at three sampling times; five QTL were for germination energy, three for germination percentage, four for germination index, and four for vigor index. Interestingly, four QTL for seed vigor, which were detected at all three sampling times, were located in the same region on chromosome 7. This result implies that this region of chromosome 7 is important for seed vigor of seeds harvested before they reach physiological maturity.     

Use of immature seed germination and single seed descent for rapid genetic gains in pigeonpea

Long duration required for generation advancement in pigeonpea [Cajanus cajan (L.) Millsp] is one of the major bottlenecks in realizing rapid genetic gains. Therefore, a technology for rapid generation turnover is warranted to facilitate the development of new cultivars and recombinant inbred lines. Breeding of early‐maturing cultivars has now opened up the possibility of rapid generation advance (RGA) in this crop. This paper reports the development of an RGA technology that integrates the germination of immature seeds with single seed descent method of breeding. The results showed that immature 35‐day‐old seeds can be used successfully to turn over a generation of pigeonpea with 100% seed germination. These way 3/4 successive generations can be grown within a year. The methodology presented in this study will accelerate the breeding process for breeding cultivars and develop rapidly the materials required for genomics research in pigeonpea.     

南阳盆地适宜机械化收获绿豆品种（系）农艺性状分析

绿豆机械化生产是未来绿豆生产可持续发展的方向。在南阳盆地种植28个绿豆品种（系）,分析其农艺性状与第1批荚果产量的关系,为适宜机械化的绿豆育种提供参考。结果表明,第1批荚果产量与其主要性状的关联顺序为单株荚数>单荚粒数>主茎节数>株高>生育期>荚长>百粒重>主茎分枝数,其中与单株荚数呈极显著的正相关性（P<0.01）,与单荚粒数、主茎节数、株高、生育期和荚长呈极显著的负相关性;通过表型聚类发现,绿豆品种（系）遗传基础狭窄,在改良适宜机械化生产性状的同时,应拓宽品种（系）的遗传背景。     

Effects of recurrent selection for resistance to scab (Gibberella zeae) in wheat

Summary Scab caused by Gibberella zeae Petch., in common wheat, is one of the most severe diseases in China. A source population C0, bred for scab resistance, was developed through three cycles of multiple-parent crossing and intercrossing by means of the dominant male-sterile gene Ta1 (Ms2), according to Wu's scheme. Phenotypic recurrent selection methods for increasing the resistance to scab-infection of spikelets and seeds with the male-sterile plants were carried out simultaneously in Nanjing and Shanghai and at Jianyang, Fujian Province, for three cycles. The generations from C0 to C3 and two check cultivars were evaluated, using a randomized block design, under conditions of an artificially induced epidemic of scab during 1988–1990. The results indicate that there were significant differences in the resistance to scab between these generations. On average, the percentages of diseased spikelets and seeds of the male-fertile plants were reduced by 9% and 10%, respectively. The frequency of resistant plants was distinctly enhanced by recurrent selection. Analysis of variance showed that no significant differences existed between cycles of recurrent selection in agronomic characters such as plant height, spikes per plant, spike length, numbers of spikelets and seeds per spike, weight of seeds per spike and 100-kernel weight, days to heading and to maturity. Except for plant height, most of these traits tended to be slightly improved with improvement of resistance in the gene pool. The variance for resistance in the generations was decreased under selection. Recurrent selection for scab resistance using the dominant male-sterile gene Ta1 (Ms2) was both an effective and feasible breeding method for producing this character in wheat.