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1.
玉米氮高效组合杂种优势分析   总被引:6,自引:1,他引:6  
在氮高效自交系筛选工作的基础上,利用NC-Ⅱ设计的材料进行杂种优势分析,同时探讨氮高效育种中亲本选配等问题。研究结果表明:氮高效类型中氮高效的生理机制各有特点,试验结果可以分为以吸收效率为主和以利用效率为主的两种杂交组合。总结亲本组成规律,氮高效组合的组配可分两大类型:①主要决定于母本的吸收和利用效率;②父母本的吸收效率和利用效率互补。所以,在氮高效育种中,要注重对母本氮效率性状的选择,尤其是氮吸收效率的选择以及亲本间氮效率性状的优势互补。在低氮条件下,注重选择母本穗粒重、行粒数、出籽率,父本的穗粒重、百粒重、穗粒数、株高、棒三叶叶面积等性状,同时考虑亲本的综合农艺性状,使氮高效组合的稳定性和适应性更强。  相似文献   

2.
玉米收获期子粒含水量相关性状的遗传及育种策略   总被引:9,自引:7,他引:9       下载免费PDF全文
收获期子粒含水量的高低严重影响玉米子粒的商品品质和生产成本.不同品种间收获期子粒含水量存在显著差异,这种差异受品种、灌浆速率、生理成熟时的含水量、脱水速率和环境等多个因素影响.收获期子粒含水量的遗传力高,狭义遗传力为77%,可进行直接选择,但在田间可通过某些相关性状进行间接选择.同时可借助RSE等选择指数选育高产、收获时含水量低的玉米杂交种。  相似文献   

3.
This experiment was conducted to study the effect of strains on productive characteristics of three genotypes of commercial pullets: Isa Brown, Bovan Nera and Dominant Black. A total number of 300 day-old chicks (100 chicks per strain) were purchased from local hatcheries. Individual body weight and linear measurements were determined from 0-20 weeks of age. There were highly significant (p < 0.01) strain differences in body weight, body length, thigh length, shank length, breast girth, feed conversion and feed efficiency. Bovan Nera recorded highest body weight, lowest feed conversion ratio and superior feed efficiency at maturity (20th week). Dominant Black on the other hand had lowest body weight, highest feed conversion and very low feed efficiency while Isa Brown recorded intermediate mean values for these traits. It was indicated in this study that regardless of strain, all the traits studied increased in mean values with advancing age of the birds. In addition, positive association between body weight and sexually maturity was established as Bovan Nera with the highest body weight at 20th week laid the first egg. The results also revealed the inverse relationship between feed conversion and feed efficiency. The former declined in mean values as the birds grew older while the latter increased simultaneously but the rate of change differs among strains. Bovan Nera was adjudged good and feed efficient because the strain had the highest mean values in body weight and feed efficiency ratio at maturity (20th week) and could be recommended to farmers for increased productivity, income generation and business sustainability.  相似文献   

4.
Efficiencies in uptake and use of N by maize cultivars have been widely studied, but little has been done on this subject in West Africa. Six single-cross hybrids, three double-cross hybrids and a synthetic line were grown at different N levels (0–210 kg N ha−1) in three ecological zones of West Africa. The maize cultivars differed widely in grain yield and N-accumulation parameters. Most cultivars absorbed similar amounts of N ranging from 2.04 g plant−1 to 2.60 g plant−1, but produced different grain yields, with those that accumulated more N after silking tending to have higher grain yield. Grain yields in the forest zone were lower than those in two Savanna regions. Differences were also observed for N-uptake (total N-uptake per unit N supplied to the soil), N-utilization (grain produced per unit N absorbed from the soil) and N-use efficiency (NUE) (grain produced per unit N supplied to the soil). Cultivars varied in their response to change in available soil N. The hybrids were more efficient in N-use and its component traits than the synthetic cultivar. Hybrid 1368 × KU1414-SR yielded the most grain as well as exhibiting superior traits for N-uptake and N-use efficiency.  相似文献   

5.
硫肥对玉米氮、磷、钾吸收利用影响的基因型差异   总被引:4,自引:1,他引:4  
以我国夏玉米主产区的34个玉米基因型(6个自交系,4个特用玉米和24个杂交种)为试验材料,通过不同硫肥供应水平的大田试验,分析了硫肥对玉米氮、磷、钾吸收利用的影响.结果表明,施用硫肥促进了玉米对营养元素的吸收,植株氮、磷、钾的积累总量平均比未施用硫肥的对照分别增加6.07%、11.89%和19.31%,肥料利用效率提高.硫肥对氮、磷、钾吸收利用的影响不完全相同,并且存在明显的基因型差异施用硫肥后,自交系氮、磷、钾的收获指数和利用效率均有大幅度提高;杂交种的氮素收获指数和利用效率均有所提高,磷素利用效率下降,但是不同基因型的变化程度差异较大;另有17个杂交种的磷素收获指数降低,10个杂交种的钾素收获指数和14个杂交种的钾素利用效率降低.  相似文献   

6.
以栽培大豆和滩涂野大豆杂交组合(N23674×BB52)亲本及其经逐代耐盐性筛选获得的4个F4∶5家系为研究对象,对其苗期耐盐性、农艺性状、籽粒品质进行了分析和比较。结果表明:F44个株系的农艺性状都介于两亲本之间。盐胁迫下F5株系幼苗的耐盐系数、干物质积累和相对生长速率高于母本栽培大豆N23674,其中4076株系最为突出。籽粒品质较其父本BB52种群有明显改善,主要表现在籽粒中蛋白质和多数必需氨基酸、含硫氨基酸含量及氨基酸总量高于双亲,粗脂肪含量介于双亲之间,且接近于其母本N23674;4076和4111株系亚油酸含量超过双亲。  相似文献   

7.
籼型两用核不育系主要农艺性状的配合力分析   总被引:26,自引:3,他引:26  
 选用5种不同来源的6个籼型两用核不育系与6个早、中籼及广亲和品种以不完全双列杂交方式组配成36个组台,此较分析了6个不育系的株高、穗长、每穗粒数、每穗实粒数、结实率、千粒重、单株穗数、单株产量及生育期9个主要农艺性状的一般配台 和特殊配合力效应以及F1优势表现。 结果表明,不育系之间的一般配台力差异很大,且与所配对应组合的F1竞争优势呈极显著相关,不 育系的一般配合力高,其 所配组合的优势也强。 一般配合力较差的不育系所配组合即使有较高的特殊配合力效应,也难有实际应用价值。3130S和衡农S-1具有较高的一般配合力效应值。作者认为不育系的配合力与其亲缘有关,采用粳籼交或栽野交可能是选育高配合力两用核不育系的有效途径。  相似文献   

8.
The Yao silkworm is a unique silkworm resource producing yellow flat plate silk that has only been reared by the Baiku Yao ethnic group in Nandan County, Guangxi Province, China for a thousand years. Here, we report the mitochondrial genomes (mitogenomes) of five Yao silkworm strains and 10 local Guangxi strains of the domestic silkworm (Bombyx mori) L. (Lepidoptera: Bombycidae), and use the resulting mitogenomes and the available Bombyx mitogenomes to characterize their genome architecture and trace the evolutionary origin of the Yao silkworm. The five Yao silkworm mitogenomes exhibited genome architectures identical to typical set of 37 mitochondrial genes (13 protein-coding genes, 22 transfer RNAs, and two ribosomal RNAs) and a high level of genome sequence similarity with the domestic silkworm. Mitogenome-based phylogenetic reconstruction provided solid evidence that the Yao silkworm shares a common ancestor with the domestic silkworm. Sliding window analysis uncovered a distinct variation pattern in the mitogenome between the Yao silkworm and the other domestic silkworm strains. The phylogenetic analyses revealed a basal placement of the Yao silkworm among all available domestic silkworm strains, indicating that the Yao silkworm is an ancient population of the domestic silkworm. Our data indicated that the Yao silkworm (B. mori) is a lineage of the domestic silkworm, which for the first time provides insights into the origin of the Yao silkworm.  相似文献   

9.
以甘蔗渣为主料,啤酒糟为主要辅料,通过研究姬菇6号、新选700、特抗650和夏抗50菌丝生长速度、长势和生物转化率等指,标优化出比较适合蔗渣栽培的平菇品种和栽培配方。正交实验极差结果显示,影响4个平菇生物转化率的主次因素为啤酒糟>麸皮。实验结果表明,添加适宜的麸皮是蔗渣栽培平菇增产的关键;姬菇6号、新选700、特抗650和夏抗50均在配方4(A2B3)上生物转化率最高,即啤酒糟15%、麸皮10%的配方上生物转化率最大,其生物转化率分别为160.06%、140.89%、178.75%和125.87%。结合4个菌株出菇时的农艺性状得出,姬菇6号比较适合以甘蔗渣为主料,啤酒糟为辅料的培养基栽培。  相似文献   

10.
卷叶水稻的光分布模拟及适宜叶面卷曲度分析   总被引:4,自引:1,他引:3  
 以叶面高度卷曲的水稻组合两优E32、中等卷曲组合两优培九和不卷曲组合汕优63为材料,引入叶面卷曲度因子,用有效叶面积指数代替传统的叶面积指数(LAI),模拟水稻冠层内的辐射传输,比较了不同叶面卷曲度因子材料的光合有效辐射截获率、转化率和利用率,探讨了不同材料的最适叶面卷曲度及最佳群体密度。结果表明,有效叶面积指数比传统的叶面积指数能更准确地预测冠层内光合有效辐射的分布。两优E32叶片过度卷曲,有效叶面积指数偏小,光合有效辐射利用率不高;而汕优63叶片平展且披散,下层叶片长期受光条件不良,光合能力弱,光合有效辐射利用率也不高。相比之下,两优培九的光合有效辐射截获率、转换率分布较为合理,光合有效辐射的利用率也较高,最适LAI为7.6,与常规栽培条件下的群体密度(LAI=7.9)接近。两优E32和汕优63的最适LAI分别为9.8和6.2,而常规栽培条件下的群体密度过小或过大,导致光合有效辐射利用率不高。利用孕穗期至齐穗期有效辐射利用率的实测值,通过输入不同的叶面卷曲度因子,得到两优E32、两优培九和汕优63的最佳叶面卷曲度因子分别为0.12、0.11和0.08,均非常接近两优培九的实际叶面卷曲度因子(0.11)。  相似文献   

11.
Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency of negative over-dominance, dominance and partial dominance was much higher than that of positive ones and heterosis, indicating that the values of F1 hybrids were generally lower than the means of their parents in quality characteristics. There existed apparent disparity in grain quality performance among F1 hybrids varied with the traits. The characteristics of chalky area percentage, chalky grain percentage, gel consistency and head rice recovery had a great variation in all kinds of tested heterosis indices including the mid-parent heterosis index, over high-value parent heterosis index and over low-value parent heterosis index, which suggested that special attention should be paid to the selection of F1 hybrids in these traits in breeding. The mean values of F1 hybrids were significantly lower than those of their higher parents in all the traits but close to or significantly lower than those of their mid-parent values except for kernel length and amylose content; and significantly higher than those of their lower parents except for brown rice recovery, milled rice recovery and gel consistency.  相似文献   

12.
不同株型玉米杂交种的产量及农艺性状的研究   总被引:7,自引:1,他引:7  
作者分析研究了目前山东省3种不同株型玉米杂交种的主要农艺性状,认为紧凑型玉米杂交种的产量最高,中间型玉米杂交种次之,平展型玉米杂交种的产量最低。紧凑型玉米杂交种高产的主要原因是由于增大密度使总粒数增多。因此,今后应大力选育和推广紧凑型玉米杂交种,以提高玉米产量。  相似文献   

13.
为了比较利用MAS选育的氮高效型恢复系及其杂交稻组合在不同氮素水平下的农艺性状差异。本研究以抗病虫害和氮高效的多基因聚合恢复系R4302、R4312及其配制的8个杂交稻组合为试验材料,‘华占’‘天优华占’为对照,设置0 kg/hm2(N0)、112.5 kg/hm2(N112.5)、150 kg/hm2(N150)、187.5 kg/hm2(N187.5)4个氮肥水平,成熟期测定与分析供试材料的单株有效穗数、单株产量、干物质产量、氮肥农学利用率、氮肥偏生产力和收获指数。结果表明,不同氮素水平下R4302各农艺性状均优于‘华占’,R4312除氮肥农学利用率外其他农艺性状优于或接近‘华占’,表明OsTCP19基因的丢失并未影响R4302、R4312氮肥的高效利用;杂交稻组合天丰A/R4302、天丰A/R4312为氮高效型组合;贵A/R4302、科20A/R4312、香龙A/R4302、科4364A/R4312为低氮高效型组合;荃9311A/R4302属于双高效型组合;科20A/R4302属于高氮高效型组合;恢复系可用单株产量、氮肥农学利用效率、干物质产量其中1项指标或有效穗数来评估氮肥的利用效率;杂交稻组合可用单株产量、干物质产量、氮肥偏生产力、氮肥农学利用率、有效穗数、收获指数其中1项指标来评估氮肥的利用效率。本研究为通过氮高效基因选育氮肥高效利用型恢复系和杂交水稻组合提供参考。  相似文献   

14.
《Field Crops Research》2004,85(1):21-30
Grain sorghum (Sorghum bicolor (L.) Moench) originated in the semi-arid tropics and is generally sensitive to low-temperature stress. Early planting and use of minimum tillage necessitate the development of sorghum hybrids with early season cold tolerance. Genetic variability for cold tolerance exists in sorghum and has been detected by early planting under field conditions and by analysis of seeds and plants under growth chamber conditions. There is limited information on the efficiency of evaluating cold tolerance under growth chamber conditions and the relationship with field performance. The objectives of this study were to quantify the variability of cold tolerance in commercial hybrid seed lots under growth chamber conditions, to exam different components of cold tolerance and their relationships, and to evaluate the consistency of lab test results with data from field tests. Thirty commercial hybrid seed lots were evaluated by growing the entries under 15/10, 13/10, 11/8, and 25/20 °C day/night temperature in a 13/11 h cycle in a growth chamber. Traits measured included emergence percentage, emergence index, shoot and root dry weight, seedling height, and vigor score. Significant genotypic differences were detected for all traits. Correlations among the traits were significant and favorable, which confirmed that simultaneous improvement of these traits should be possible. The same seed lots were also evaluated in a soil-free plate-based assay, in which percent germination, and shoot and root elongation of the seed lots grown in dark at 15 °C were measured. Results from both laboratory tests, soil-based and plate-based, were correlated with data collected in a field study, which was conducted to evaluate cold tolerance of commercial sorghum hybrids at Manhattan, Hesston, Bellville, and Garden City, KS in 1998 and 1999. Single-trait correlations between lab and field studies were significant. Differentiation based on rank-summation index of common traits, rank-summation index correlations and the overlap of best entries, further provided strong support of the efficiency of predicting and identifying elite hybrids using growth chamber assays.  相似文献   

15.
Source-Sink Relationship in Intersubspecific Hybrid Rice   总被引:1,自引:0,他引:1  
The yields of rice crop increased drastically after the beginning of rice green revolution symbolized by utilizing semi-dwarfing gene and the dissemination of hybrid rice. The increase in rice yield not only can handle the food crises in China but also ac…  相似文献   

16.
Lactic acid is widely used in the food, drugs, cosmetics, and other industries to maintain the microbial stability of low-pH products. However, it is unclear whether lactic acid can affect silkworm (Bombyx mori) growth and reproduction. This study investigated the effects of lactic acid on the growth and reproduction of the silkworm. We analyzed the growth, cocoon quality, and reproductive performance of fifth instar larvae fed on mulberry leaves saturated with different concentrations (0.01, 0.1, 1, and 10%) of lactic acid and the control. Results showed that 0.01, 0.1, and 1% lactic acid supplementation positively affects growth and female cocoon quality, with increased larval weight and female cocoon shell weight compared to the control group. In contrast, 10% lactic acid was toxic to the larvae and significantly decreased growth, leading to larval death. Our study provides a basic reference for the optimal amount of preservatives. In addition, this study can be a desirable intervention for sericulturists and can play an important role in getting high return from silkworm-rearing activities.  相似文献   

17.
试验选择不同氮效率的超高产玉米杂交种为材料,应用裂区设计,通过逐步回归和相关分析,研究氮高效杂交种穗三叶生理特性及穗三叶氮积累特点,明确穗三叶氮积累量及生理特性对氮效率的贡献。结果表明,不论是否施用氮肥,吸收效率对氮效率的贡献均高于利用效率,是氮效率差异的主要来源,且高效型杂交种吐丝期穗三叶含氮量及转移量均高于低效型。低氮下,穗三叶吐丝期含氮量、光合速率、胞间CO2浓度、穗三叶硝酸还原酶含量对氮效率的贡献较大,是低氮高效品种筛选的重要指标;高氮下,穗三叶吐丝期含氮量、光合速率、穗三叶硝酸还原酶含量对氮效率贡献较大,是高氮高效品种筛选的重要指标。  相似文献   

18.
Hybrid rice (Oryza sativa L.) has been proven to be effective in increasing yield potential, but lodging often limits its yield in high-yielding environments. This study was conducted to determine genotypic variation in lodging resistance and lodging-related morphological traits among hybrid and non-hybrid check varieties, and to identify the key morphological traits associated with lodging resistance. Lodging behavior of 16 rice genotypes, including 12 hybrids and four inbreds, was studied at the International Rice Research Institute farm during the 2004 wet season (WS) and 2005 dry season (DS). Grain yield and visual score of lodging were determined at maturity. Lodging-related morphological traits were measured at 30 days after flowering. Large genotypic differences in lodging-related morphological traits were observed. Among these traits, dry weight per unit length, breaking resistance, and lodging index (bending moment/breaking resistance × 100) of lower internodes were significantly correlated with visual score of lodging. Several hybrids demonstrated high lodging resistance although their average plant height was over 120 cm. The lodging-related morphological traits and visual score of lodging in these hybrids were comparable with those of the non-hybrid check varieties with strong lodging resistance. These results suggest that increases in dry weight per unit length and breaking resistance of lower internodes are primary targets for reducing lodging index, thus improving overall lodging resistance of hybrid rice in a breeding program.  相似文献   

19.
马铃薯体细胞杂种的青枯病抗性鉴定   总被引:3,自引:0,他引:3  
本试验对马铃薯四倍体栽培种(Solanum tuberosum)的双单倍体系81-15与二倍体野生种S.cha-coense的原生质体融合株系进行了青枯病抗性鉴定,其目的是对利用体细胞融合技术获得抗青枯病种质的有效性及抗性鉴定技术进行评价,获得抗病育种材料。结果表明:在鉴定的18个体细胞融合株系中,抗性分离表现为从感病(S)到抗病(R),多数表现为中感(MS)到中抗(MR)水平。田间病圃鉴定、人工接种鉴定和分子标记鉴定的结果显示:田间病圃鉴定的病情指数(DI)和人工接种鉴定病级(DS)的相关性达到极显著水平(DI=-0.39+4 DS,r2=0.921),双侧翼SCAR标记SCA07446和SCA12980鉴定同时具有两个标记特异带的株系均为前两种鉴定表现为中感(MS)以上的材料。综合分析同时利用3种方法鉴定的结果:CHT-3、CHT-5、CHT-6、CHT-10、CHT-15等5个株系为抗病材料,证明体细胞融合是利用野生种质资源抗性的有效途径。  相似文献   

20.
以郑单958(耐旱性强)和驻玉309(耐旱性弱)为供试材料,通过池栽试验研究水分胁迫对两个玉米品种的吐丝前后土壤水消耗、水分利用和子粒产量的影响。正常供水下,两个品种吐丝前和吐丝后土壤水消耗量、生育期耗水量、水分利用效率和子粒产量均无显著差异。水分胁迫下,全生育期各土层(0.2~1.6 m)水分消耗量均为郑单958少于驻玉309,吐丝前和吐丝后郑单958土壤水消耗量分别比驻玉309少12 mm和21mm,且分别以0.2~0.4 m(吐丝前)和0.8~1.0 m(吐丝后)土层品种间差异最大。水分胁迫下,郑单958和驻玉309的生育期耗水量分别为454 mm和487 mm,子粒产量分别为8 320 kg/hm~2和7 290 kg/hm~2,表明水分胁迫条件下,耐旱品种郑单958以较少的水分消耗生产更多子粒,表现出较高的水分利用效率。  相似文献   

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