Agronomic and physiological contributions to the yield improvement of soybean cultivars released from 1950 to 2006 in Northeast China

Increasing yield is a high priority in most breeding programs. Approximately 600 soybean cultivars had been released by the end of the last century in Northeast China. Understanding the agronomic and physiological changes is essential for planning further plant breeding strategies in soybean. In this study, 45 representative soybean cultivars, from maturity groups 00 and 0, released from 1950 to 2006 in Northeast China were compared in field conditions for 3 consecutive years. A positive correlation between seed yield and year of cultivar release was indicated with a 0.58% average annual increase. Seed number per plant was the most important contributor to yield gain, with a 0.41% increase per year. Pod number per plant and seed size varied slightly with the year of cultivar release. Although variation in protein was from 37.0% to 45.5%, and oil concentration was from 16.7% to 22.0%, their concentrations were not consistently related to year of cultivar release. A 33% increase in the photosynthetic rate, 10.6% increase in plant dry weight and 19.0% increase in harvest index (HI) were found, while leaf area index (LAI) decreased by 17.3%. Modern cultivars have higher photosynthetic rates than their predecessors. The reduced plant height gave increased resistance to lodging, with the lodging score dropping from 3.2 in 1951 to 1.0 in 2006. Seed resistances to disease and pest infestation were also improved. Yield stability was enhanced over years, which could be attributed to the stable pod production across different environments. A flow diagram to explain the contributors to genetic improvement of soybeans in Northeast China was developed.     

大豆种子活力相关性状优异等位变异的发掘

发掘与大豆种子活力性状相关联的标记及优异等位变异是选育高活力品种的基础。本研究利用标准发芽实验对我国北方地区174份大豆品种7个种子活力相关性状进行连续两年（2018-2019年）的表型鉴定,并结合覆盖大豆20条染色体上的210对SSR标记进行表型和标记的关联分析。结果表明：供试品种表型变异系数为15.58%~38.31%。将群体划分为2个亚群,检测到27个与活力性状相关联的标记,累计60个（次）,其中24个SSR标记在两年共同被检测到,对表型变异解释率为2.68%~23.60%,Sat-267对苗长的表型变异解释率最高,为23.60%,Satt250对发芽势的表型变异解释率为23.15%;标记Satt311、Satt250、Satt606、Satt-267与两个以上的活力性状关联。共获得108个增效优异等位变异及相应的载体材料,其中Satt250-217bp对侧根长的增效值最大,并对发芽势也具有增效作用;典型载体材料北疆1号和合农75号携带了两个以上活力性状的最大增效等位变异。     

大豆耐盐碱种质资源鉴定

盐碱胁迫伴随作物生长各个阶段,筛选获得全生育期耐盐碱大豆资源意义重大。试验通过测定大庆地区盐碱土含盐碱种类、含盐量及pH值等指标,确定筛选用盐碱种类、浓度。在培养皿、发芽袋和盆栽试验筛选中,通过大豆芽期发芽率、芽苗期物质生长量、成熟期物质生长量鉴定耐盐碱大豆种质。结果显示大庆地区盐碱土壤为硫酸盐苏打盐碱土,确定盐碱溶液为NaCl、Na₂CO₃、NaHCO₃和Na₂SO₄（摩尔比为1∶1∶9∶9）的混合盐碱溶液,以Na离子含量计算总盐浓度为80 mmol·L^-1,溶液pH值为8.9,盆栽筛选用土壤盐含量为3.3‰,pH值为8.9。鉴定的887份种质资源中种皮颜色有黑、褐、红、绿、黄及双色等,相关性分析发现大豆耐盐碱性与大豆种皮颜色极显著正相关。通过芽期耐盐碱鉴定,887份大豆资源中筛选获得296份耐以上资源,进一步芽苗期筛选有123份显示高耐,再经过全生育期筛选获得7份高耐资源,5份来源于南方,2份来源于黄淮,62份耐资源,盆栽筛选比例为56.10%。本研究建立了从芽期、芽苗期到全生育期的逐级筛选方法,从887份大豆种质资源中筛选获得69份耐盐碱资源,为耐盐碱育种与耐盐碱基因资源利用提供基础材料。     

Yield,protein, and oil quality of soybean genotypes selected for tofu production

The soyfood industry prefers some soybean [( Glycine max L. (Merr.)] cultivars over others based on chemical constituents, physical traits, and processing quality of the seed. However, soybean cultivars possessing the combination of desirable agronomic traits and biochemical characteristics that enhance the quality of soyfoods have not been identified in the U.S. Thus, this research was conducted with the objective of determining yield, seed protein, and fatty acid composition of soybean genotypes selected for tofu production. Twelve soybean genotypes were planted in plots arranged in a randomized complete block design with four replications at the Agricultural Research Station, Fort Valley State University, Georgia during 1994 and 1995. Seed yield ranged from 1.6 to 3.0 metric tons/ha. The protein content varied between 314.2 and 480.7 g/kg seed. Both BARC-8 and BARC-9 had significantly higher protein content than other genotypes. These two genotypes also showed significant year by genotype interactions for some fatty acids. V71-370 had the highest oleic acid concentration and a high ratio (0.92) of monounsaturated to polyunsaturated fatty acids. The concentration of linoleic and linolenic acids ranged from 406.5 to 531.0 and 37.1 to 63.0 g/kg oil, respectively. Seed yield was correlated with biomass, harvest index, and filled pods per m2. In this study, V71-370 was found to be relatively superior in oil quality with fatty acid composition desirable for human consumption. The significant variation for seed yield and biochemical characteristics observed among the few genotypes examined in this study indicates the potential for breeding high yielding soybean cultivars suitable for soyfoods. Therefore, there is a need for evaluation of soybean germplasm for agronomic traits that contribute to seed yield and biochemical characteristics including fatty acid profiles that enhance soyfood quality before initiating development of suitable cultivars for tofu.     

2013-2015年中国冬小麦种子发芽率及高活力关联物理性状的检测

为了解中国冬小麦种子市场的种子质量情况,连续三年(2013-2015)收集全国冬小麦主产区市场上的冬小麦种子样品共计756份,进行了种子发芽率普查和活力检测,并对与品种种子高活力相关联的物理性状进行了分析.结果表明,全国冬小麦种子标准发芽率在三年内有所提升,分别为83.6％、92.8％和93.0％;在不同地区收集到的同一冬小麦品种种子标准发芽率基本一致,但其耐盐性、抗旱性和耐老化能力均在地区间略有差异.在与种子活力有关的物理性状中,千粒重和种子厚度与种子活力相关性高且稳定.当种子萌发期条件较好时,千粒重49.54～50.30 g、厚度3.20～3.29 mm的冬小麦种子萌发较好;当种子萌发期逆境胁迫较强时,则应选择千粒重33.83～34.50 g、厚度2.76～2.84 mm的冬小麦品种.     

啤酒大麦种子在成熟过程中品质形成的研究

以 4个啤酒大麦品种 ,研究啤酒大麦种子在种子发育过程中啤酒大麦品质的形成 ,结果表明 :啤酒大麦种子的千粒重随种子的成熟呈直线上升的趋势 ,而蛋白质的含量在种子成熟过程中变化较小 ,呈波状变化 ;抽穗后 36d内随种子的发育成熟 ,发芽率呈上升的趋势 ,抽穗后 36d是大麦种子最佳收获时间 ,此时收获的大麦种子具较高的发芽势与发芽率相对应的 ,此时收获的大麦种子活力、POD和a -淀粉酶活性也最高     

In situ sprouting and regulation of fresh-seed dormancy in Spanish type groundnut (Arachis hypogaea L.)

Two hundred groundnut (Arachis hypogaea L.) germplasm accessions and 21 cultivars belonging to the Spanish group (ssp. fastigiata var. vulgaris) were screened for pod loss due to sprouting of seed in the field. Some cultivars were also tested for germination of the fresh-seed with or without testa and treated or untreated with ethrel or abscisic acid (ABA). Large variation in pod loss due to in situ sprouting of seed, and fresh-seed dormancy (FSD) was found among the accessions and cultivars. Fresh-seed dormancy index (FSDI) varied from 2% in Chico to 88% in ICGS 44 (the check with high FSD). Cultivars with an FSDI value of less than 10% showed more pod loss in situ than the cultivars with high FSDI. Thus pod loss due to in situ sprouting increased with a decrease in FSDI. Cultivar SB XI did not show any in situ sprouting or pod loss. A direct relationship (r, 0.86^**) existed between fresh-seed germination of accession/cultivar in the laboratory and the percentage of its plants with sprouted seed in the field. Seed of two Spanish cultivars ICGS 11 (dormant) and GG 2 (non-dormant) when tested for germination after treatment with ethrel or ABA at various seed development stages showed different germination response to these chemicals. Seed of GG 2 showed up to 40% germination even at an early stage (S₁) of seed development, whereas the seed of ICGS 11 responded to the ethrel only at maturity (S₄). Regulation of FSD appeared to be more under the control of the testa than the cotyledons. The variation in the degree of in situ sprouting can be used for breeding Spanish cultivars with various desirable levels of FSD.     

中国大豆种质资源对大豆孢囊线虫3号生理小种抗性鉴定研究

１９９１－１９９５年，应用田间自然病圆和病土盆栽鉴定方法，对安徽、河北、福建、山东等２４个省市保存的３３５５份栽培大豆种质资源和１８６份野生大豆种质资源分别进行大豆孢囊线虫３号生理小种的抗性鉴定。     

吉林、辽宁大豆品种(系)对大豆疫病的抗病基因鉴定

采用下胚轴伤口接种法评价了吉林和辽宁省49个主栽品种(系)对Phytophthora sojae13个不同致病型标准菌系的抗性。与鉴别寄主的比较分析表明,铁丰29,吉育67,沈农9号,吉育80推导含有Rps3a基因;铁丰31,吉育45,吉育90,九农34,铁豆42,铁豆43,铁豆44推导含有Rps3a和Rps1d双基因;辽豆18推导含有Rps3a和Rps1k双基因;辽豆17推导含有Rps1d和Rps6双基因;辽豆21,辽豆22和辽豆24推导含有Rps1a基因;九农29和九农35推导含有Rps1k基因。     

不同氮源对大豆硝酸还原酶和谷氨酰胺合成酶活性及蛋白质含量的影响

利用硝态氮(NO3--N)、铵态氮(NH4 -N)及混合态氮对4个栽培大豆品种结荚期植株进行诱导处理,研究不同氮源对叶片硝酸还原酶(NR)、谷氨酰胺合成酶(GS)活性以及子粒蛋白质含量的影响.结果表明,NO3--N增加4个品种NR活性效果最好,其次是混合态氮,而NH4 -N的效果较差.从4个品种叶片的GS活性看,混合态氮和NH4 -N的处理效果好,而NO3--N的效果差;三种氮源处理4个基因型的子粒蛋白质含量都有不同程度的增加,增加的顺序与提高NR活性的顺序相同.说明施用三种氮肥能增加大豆品种子粒的蛋白质含量,而以施用硝酸钾的效果最佳.相关分析表明,大豆叶片NR活性与子粒蛋白质含量之间呈极显著正相关(r=0.663**),可以把结荚期叶片的硝酸还原酶活性作为选择高蛋白大豆材料的参考指标之一.     

不同大豆种质种子耐浸水能力鉴定

播种后遭遇渍害是南方夏大豆生产面临的主要逆境危害之一。为研究不同大豆种质播后对浸水耐性差异表现，以种子浸种120h模拟渍害条件，测定137份大豆材料浸泡液电导率，并进行标准发芽试验，统计种子发芽势（GPP）、发芽率（GP）、正常苗率（NSP）等指标，并利用主成分分析、聚类分析等分析方法对多个指标进行多元统计分析，利用综合耐浸水指标及简易指标对大豆种子耐浸水能力进行等级划分，筛选耐浸水能力强的大豆材料。结果表明，浸水处理120h后，GPP、GP、NSP、轻微损伤粒率（SISP）、严重损伤粒率（IBSP）、烂粒率（DSP）及电导率等6个指标的变异系数均大于50%，GPP、GP和NSP同大豆百粒重呈显著负相关，电导率同百粒重呈显著正相关。利用主成分分析提取两个主成分：“健康因子”和“过渡因子”，贡献率分别为64.45%和15.83%，根据两因子得分矩阵进行聚类分析，可将供试材料划分为3类。利用综合指标法将137份大豆材料划分为5种耐浸水级别，表现耐浸水的大豆材料9份，并在GP、GPP、NSP三个简易耐浸水指标筛选中同时表现耐浸水的大豆材料5份，可作为进一步筛选鉴定的对照种质资源。大豆浸泡液电导率与种子正常苗率相结合可作为大批量筛选耐浸水种质的指标。     

包衣对大豆生长发育和产量的影响

通过用三种包衣剂对大豆种子包衣的研究,结果表明：大豆种子包衣后,种子的发芽势、发芽率、活力指数均优于不包衣种子,但包衣与不包衣种子的发芽率、发芽势、活力指数差异均未达显著水平。三种包衣剂都能协调大豆的营养生长和生殖生长的关系,增加百粒重,提高产量,其中2号包衣刺产量增加15．51％,差异达极显著水平,1号包衣刺产量增加1.31％,差异不显著,3号包衣剂增产4、49％,差异不显著。     

春大豆种子劣变的研究

用不同地理来源的９个春大豆品种，进行了两年春，秋两季播种，及播期与收获时期试验，研究种子劣变过程及其影响因素。结果显示：春大豆种子的劣变，收获前劣变起主导作用，高温高湿气候影响种子发育则为主要原因。收获前种子劣变并非真菌感染所致。播季间，播期间及收获时间不同，种子劣变差异显著，春播提早播种及秋播是获得高活力种子的途径。收获后种子劣变与贮藏条件有关，高温高湿加速劣变。干燥，密闭贮藏能减轻种子劣变速度，短期贮藏（９个月以内）减轻效果不显著，随贮藏时间延长（１２个月以上）则干燥贮藏显著减缓种子劣变。本文同时对种子劣变过程与生产高质量种子以及抗性遗传育种作了探讨。     

Anatomical Changes during in Vitro Direct Formation of Shoot Bud from Root Tips in Garlic (Allium sativum L.)

Abstract

The germination and emergence of soybean [Glycine max (L.) Merr.] can be adversely affected by the presence of excessive water as a result of continuous rainfall. The pre-germination flooding-tolerant cultivars can be tolerant to hypoxia in the flooding field. The objective of this study was to clarify the relationship between germination under hypoxia at different temperatures and pre-germination flooding tolerance. Seeds of 6 soybean cultivars were subjected to 5 oxygen concentrations and 3 temperatures. Seeds of all 6 cultivars hardly germinated under an oxygen concentration of 20 mL L^–1, but germinated with increasing oxygen concentration regardless of temperature. The pre-germination flooding-tolerant cultivar ‘Peking’ exhibited poorer germination under hypoxia than the other cultivars. Seed coat of ‘Peking’ did not dehisce when seeds did not germinate under hypoxia regardless of temperature. The pre-germination flooding-susceptible cultivar ‘Nakasennari’ exhibited higher seed coat dehiscence, but the dehiscence mostly occurred on the seed surface rather than micropyle under hypoxia at 25°C and 30°C. Seven days after termination of 3-d hypoxia treatment at 30°C, the percentage of seedlings with root hairs and/or lateral roots relative to that after ambient oxygen treatment was maintained in ‘Peking’ but decreased in the other cultivars, especially in ‘Nakasennari’. Pre-germination flooding-tolerant cultivar, especially ‘Peking’, is characterized by a delay in germination processes under hypoxia, and exhibits vigorous germination after release from hypoxia.     

Seed variation among annual ryegrass cultivars in south-eastern USA and the relationship with seedling vigour and forage production

Abstract Annual ryegrass (Lolium multiflorum Lam.) is grown on more than one million ha in the south‐eastern USA each year. Recommended and actual seeding rates vary substantially within the region. The objective of this study was to evaluate variation in seed weight, germination, seedling vigour and seasonal yield performance among annual ryegrass cultivars. During 1997, 1998 and 1999, seed from fourteen commercial cultivars was weighed and germinated to determine numbers of pure live seed (PLS) m^?2 before yield evaluation at four locations. Seed from ten cultivars was planted at 0·7 and 2·0 cm depth in a greenhouse study to evaluate relative seedling vigour. Cultivar mean single‐seed weight ranged from 2·4 to 4·8 mg in 1997, 1·8 to 4·5 mg in 1998, and 2·6 to 4·6 mg in 1999. Seed germination ranged from 78·8% to 98·0% in 1997, 82·3 to 98·3% in 1998 and 77·8 to 98·3% in 1999. Seed number, PLS m^?2, ranged from 675 to 1289 in 1997, 710 to 1550 in 1998, and 717 to 1179 in 1999. Among the ten cultivars evaluated for seedling vigour, seedling weight differed between planting depths and a significant cultivar by year interaction was observed. Seedling weight was highly correlated with seed weight at each seeding depth. The effect of increasing number of PLS m^?2 on subsequent yield performance, although small, was consistently negative. These results indicate that target plant populations may be obtained more economically by adjusting seeding rates for seed size differences among cultivars and seed lots of annual ryegrass.     

干旱胁迫对不同抗旱性小麦种子萌发及幼苗根芽生物量分配的影响

为探讨冬小麦种子萌发期抗旱性与幼苗生物量分配的关系,以小麦抗旱型品种长旱58和干旱敏感型品种漯麦18为材料,采用聚乙二醇(PEG-6000)模拟干旱胁迫的方法,测定和分析了干旱胁迫后小麦种子发芽率、幼苗根冠比、叶绿素含量等16个指标的变化。结果表明,干旱胁迫后,长旱58种子发芽率无明显变化,漯麦18种子发芽率显著下降。干旱胁迫下长旱58种子发芽势、发芽指数、活力指数和干物质转移量显著大于漯麦18,平均发芽时间显著小于漯麦18,长旱58幼苗根、芽的长度和干重及总干重均显著高于漯麦18。干旱胁迫显著增加漯麦18幼苗根冠比,对长旱58萌发第五和第七天的幼苗根冠比无显著影响。干旱胁迫显著降低漯麦18幼苗叶绿素含量,对长旱58无显著影响。由于小麦萌发期幼苗干物质累积取决于种子中营养物质的转移和呼吸消耗,因此推测种子营养物质的快速转移和低呼吸消耗有助于提高小麦萌发期的抗旱能力,促进干旱胁迫下种子萌发和幼苗生长。     

Seed quality as affected by nitrogen during true potato seed production and moisture conditions during storage

The objective was to investigate the effects of moisture conditions in storage at 21 C (± 3) on true potato seed (TPS) germination and seedling vigor. The influence of supplemental nitrogen (N) during seed production on these effects was also studied. One set of TPS was stored exposed to ambient humid (> 80% RH) air; the other was stored dry (sealed with silica gel). Germination tests were performed at 7, 11, and 14 months of seed storage. Seedling vigor tests were made at 14, 20, and 23 months. The rate of germination was mostly affected by the moisture conditions during storage. Seed stored dry germinated faster than TPS stored in humid ambient air. The rate of germination increased with time in storage and the percentage of germination was always high (≥ 95%) in dry seed produced with high N. Seedling vigor was mostly affected by N treatments during seed production. High-N seed had a much higher rate and percentage of emergence and seedling dry-weight levels than low-N seed, particularly when stored dry. Seedling vigor criteria decreased with time in storage in low-N seed; in high-N seed, the rate of emergence increased and the percentage of emergence was always high (≥ 95%). In conclusion, the TPS should be produced with high N and stored dry for sowing under unfavorable conditions.     

Morphological and physiological traits of seeds and seedlings in two rice cultivars with contrasting early vigor

Early vigor is important for crop establishment in rice. This study was conducted to determine the seed and seedling traits in relation to early vigor in rice. Laboratory tests and pot experiments were carried out in 2013 and 2014. Morphological and physiological traits of seeds and seedlings were compared between two contrasting rice cultivars, Yuxiangyouzhan with superior early vigor and Huanghuazhan with general early vigor. For seed traits, Yuxiangyouzhan had lower seed hull weight but higher seed amylose content, seed amylase activity, and plumule–radicle ratio than Huanghuazhan, and consequently, Yuxiangyouzhan had about 10% higher germination percentage and velocity and 37% longer plumule than Huanghuazhan. For seedling traits, leaf area, specific leaf weight, leaf chlorophyll and soluble protein contents, leaf net photosynthetic rate, and shoot–root ratio were higher in Yuxiangyouzhan than in Huanghuazhan, and as a result, seedling shoot biomass was 23–32% higher in Yuxiangyouzhan than in Huanghuazhan. These results indicate that Yuxiangyouzhan has both superior seed and seedling vigor. The former is attributed to the low mechanical strength of seed hull, high conversion efficiency of seed reserve, and high mobilization of seed reserve to plumule, while the latter is due to large leaf area, high leaf photosynthetic capacity, and high partitioning of dry matter to shoot. This study enriches the physiological understanding of superior early vigor in rice.     

甲醇老化处理对玉米种子发芽和幼苗生长的影响

分析不同时间的50%甲醇老化处理对玉米种子发芽和幼苗生长的影响,明确甲醇老化处理的最佳时间。结果表明,与蒸馏水浸泡40 min(CK)相比,50%甲醇老化处理10~30 min时种子发芽指标(活力指数除外)均无显著变化;40 min时种子发芽率、发芽势、发芽指数、活力指数分别降低5.67%、8.67%、11.08%和41.22%;50 min时分别降低6.00%、10.00%、18.05%和47.70%;60 min时分别降低21.33%、28.00%、35.62%和61.80%;70 min时种子发芽指标降至较低水平。甲醇老化处理10 min时,玉米幼苗苗高、根长、根苗比、苗重和根重均显著降低,且降低幅度高于发芽指标。与CK相比,甲醇老化处理10~30 min时对种子脱氢酶活性和相对电导率无显著影响,40~70 min时脱氢酶活性显著降低,相对电导率显著增加。因此,50%甲醇老化处理应选择40~60 min为宜。     

H2O2浸种对低温胁迫下花生种子萌发的调控作用

为了研究H2O2浸种对低温胁迫下花生种子萌发的调控作用，本研究以白沙1016和花育9122两个花生品 种为材料，通过种子萌发试验，设置（22±1）℃常温对照和（12±1）℃低温处理，首先采用不同浓度的H2O2进行浸种预 处理，分析了H2O2浸种对花生种子低温萌发相关指标的影响，筛选最适H2O2浸种浓度，然后采用最适H2O2浸种处 理后，测定其对发芽花生种子胚中氧化损伤和活性氧含量、脯氨酸代谢相关指标的影响。结果表明，低温显著降低 两个品种花生的相对发芽率、芽长/种长比、发芽指数及种子的活力指数，延长了平均露白时间，H2O2浸种预处理可 显著缓解低温对花生种子萌发的抑制，以1% H2O2浸种效果最好。同时，H2O2浸种预处理还显著降低了H2O2的积累 以及膜脂过氧化程度，促进了脯氨酸的积累，提高了脯氨酸合成酶鸟氨酸转移酶（OAT）和△1-吡咯琳-5-羧酸合成 酶（P5CS）活性，抑制了脯氨酸降解限速酶脯氨酸脱氢酶（ProDH）活性。表明H2O2浸种预处理可通过调控脯氨酸代 谢途径，促进低温条件下萌发花生种子内脯氨酸的积累，缓解氧化损伤，从而增强花生种子的低温萌发能力。