Introgression of QTL from Aegilops tauschii enhances yield-related traits in common wheat

To break the narrow diversity bottleneck of the wheat D genome, a set of Aegilops tauschii-wheat introgression(A-WI) lines was developed by crossing Ae. tauschii accession T015 with common wheat elite cultivar Zhoumai 18(Zhou18). A high-density genetic map was constructed based on Single Nucleotide Polymorphism(SNP) markers and 15 yield-related traits were evaluated in 11 environments for detecting quantitative trait loci(QTL). A total of 27 environmentally stable QTL were identified in at least five environments, 20 of which were derived from Ae. tauschii T015, explaining up to 24.27% of the phenotypic variations. The major QTL for kernel length(KL), QKl-2D.5, was delimited to a physical interval of approximately 2.6 Mb harboring 52 candidate genes. Three Kompetitive Allele Specific PCR(KASP)markers were successfully developed based on nonsynonymous nucleotide mutations of candidate gene AetT093_2Dv1G100900.1 and showed that A-WI lines with the T015 haplotype had significantly longer KL than the Zhou18 haplotype across all 11 environments. Four primary valuable A-WIs with good trait performance and carrying yield-related QTL were selected for breeding improvement. The results will facilitate the efficient transfer of beneficial genes from Ae. tauschii into wheat cultivars to improve wheat yield and other traits.

Genome-wide association study exposed the pleiotropic genes for yield-related and oil quality traits in Brassica napus L.

Oilseed rape(Brassica napus L.) is an allotetraploid(AACC,2n=38) crop,valued for its edible oil and protein content.seed yield and nutritional composition of rapeseed are influenced by its yield and oil quality traits.However,the genetic basis of yield-related and oil-quality traits remain ambiguous.A panel of 266 diversified oilseed rape accessions was genotyped using 223 simple sequence repeat(SSR) markers covering all 19 chromosomes to identify significant markers associated with yield and quality traits.Twelve yield-related and six quality traits were investigated in two consecutive years(2014 and 2015),with three replications in two environments(Changshun,CS;and Qinghe,QH).Using the model GLM with population structure and kinship(Q+K),a total of 25 significant SSR markers(P <0.001) were detected to be associated with these twelve yield-related and six quality traits,explaining 4.56%-19.17% of the phenotypic variation for each trait.Based on these markers,BnaA03g23490D, BnaC09g46370D,BnaA07g37150D,BnaA01g32590D, and BnaC09g37280D were identified as pleiotropic genes controlling multiple traits.These candidate genes illustrated the potential for the genetic understanding of yield and oil quality traits.Most importantly,these significant markers can be used for marker-assisted breeding of oilseed rape in different environments.

Correlation Analysis and Path Analysis between Yield and Yield-Related Traits of Yunmai 52

[Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of yield-related traits to the yield of Yunmai 52 clear. [Method] Wheat variety regional trial data in Yunnan Province in 2005-2007 were subjected to correlation analysis and path analysis in the paper. [Result] Correlationanalysis showed that the yield of Yunmai 52 was in- very significant positive correlation with spikelet number per ear, maximum tiller number and grains per ear （r=0.726^＊＊, 0.717^＊＊ and 0.695^＊＊, respectively）, in signif- icant positive correlation with 1 000-grain weight （r=0.491^＊）, but in significant nega- tive correlation with sterile spikelet number per ear, and in non-significant correlation with basic seedlings, effective ears and percentage of ear bearing tillers. Partial correlation analysis showed that the yield of Yunmai 52 was in very significant posi- tive correlation with spikelet number per ear （r=0.711^＊＊）, significant positive correla- tion with 1 000-grain weight （r=0.641 =）, but in non-significant correlation with other 6 traits. Path analysis showed that spikelet number per ear （P=-0.595）, maximum tiller number （P=0.462） and t 000-grain weight （P=0.263） had more contribution to yield of Yunmai 52. [Conclusion] Therefore, in extension and application of Yunmal 52 that is a high-quality high-yield multi-resistant new wheat variety, supply of fertilizer and water should be increased in tillering stage and jointing stage, to ensure its characteristics of high tilledng ability and large ear, as well as high 1 000-grain weight, and coordinated development of other yield-related traits is beneficial to im- provement of yield of Yunmai 52.

Identification of QTLs for Yield-Related Traits in the Recombinant Inbred Line Population Derived from the Cross Between a Synthetic Hexaploid Wheat-Derived Variety Chuanmai 42 and a Chinese Elite Variety Chuannong 16

Synthetic hexaploid wheat （SHW） represents a valuable source of new resistances to a range of biotic and abiotic stresses. A recombinant inbred line （RIL） population with 127 recombinant inbred lines derived from a SHW-derived variety Chuanmai 42 crossing with a Chinese spring wheat variety Chuannong 16 was used to map QTLs for agronomic traits including grain yield, grains per square meter, thousand-kernel weight, spikes per square meter, grain number per spike, grains weight per spike, and biomass yield. The population was genotyped using 184 simple-sequence repeat （SSR） markers and 34 sequence-related amplified polymorphism （SRAP） markers. Of 76 QTLs （LOD〉2.5） identified, 42 were found to have a positive effect from Chuanmai 42. The QTL QGy.saas-4D.2 associated with grain yield on chromosome 4D was detected in four of the six environments and the combined analysis, and the mean yield, across six environments, of individuals carrying the Chuanmai 42 allele at this locus was 8.9% higher than that of those lines carrying the Chuannong 16 allele. Seven clusters of the yield-coincident QTLs were detected on 1A, 4A, 3B, 5B, 4D, and 7D.

Response of phenology- and yield-related traits of maize to elevated temperature in a temperate region

Extreme high temperatures detrimental to maize production are projected to occur more frequently with future climate change.Phenology and yield-related traits were investigated under several levels of elevated temperature in two early-maturing hybrid cultivars:Junda 6(grown in northeastern China)and Chalok 1(grown in South Korea).They were cultivated in plastic houses in Suwon,Korea(37.27°N,126.99°E)held at target temperatures of ambient(AT),AT+1.5°C,AT+3°C,and AT+5°C at one sowing date in 2013 and three different sowing dates in 2014.Vegetative and reproductive growth durations showed variation depending on sowing date,experimental year,and cultivar.Growth duration tended to decrease,but not necessarily,with temperature elevation,but somewhat increased again above a certain temperature.High temperature-dependent variation was greater during grain filling than in the vegetative period before anthesis.Elevated temperature showed no significant effects on duration or peak dates of silking and anthesis,and thus on anthesis–silking interval.Grain yield tended to decrease with temperature elevation above ambient,showing a sharper linear decrease with mean growing season temperature increase in Junda 6 than in Chalok 1.The decrease in kernel number accounted for a much greater contribution to the yield reductions due to temperature elevation than did the decrease in individual kernel weight in both cultivars.Individual harvestable kernel weight was not significantly affected by temperature elevation treatments.Kernel number showed a linear decrease with mean growth temperature from early ear formation to early grain-filling stage,with Junda 6 showing a much severer decrease than Chalok 1.Kernel number reduction due to temperature elevation was attributable more to the decrease in differentiated ovule number than to the decrease in kernel set in Chalok 1,but largely to the decrease of kernel set in Junda 6.

Association mapping and domestication analysis to dissect genetic improvement process of upland cotton yield-related traits in China

Background: Cotton fiber yield is a complex trait,which can be influenced by multiple agronomic traits.Unravelling the genetic basis of cotton fiber yield-related traits contributes to genetic improvement of cotton.Results: In this study,503 upland cotton varieties covering the four breeding stages(BS1–BS4,1911–2011)in China were used for association mapping and domestication analysis.One hundred and forty SSR markers significantly associated with ten fiber yield-related traits were identified,among which,29 markers showed an increasing trend contribution to cotton yield-related traits from BS1 to BS4,and 26 markers showed decreased trend effect.Four favorable alleles of 9 major loci(R^(2)≥3)were strongly selected during the breeding stages,and the candidate genes of the four strongly selected alleles were predicated according to the gene function annotation and tissue expression data.Conclusions :The study not only uncovers the genetic basis of 10 cotton yield-related traits but also provides genetic evidence for cotton improvement during the cotton breeding process in China.

Identifying Genomic Regions Conferring Morphological and Yield-related Traits in Soybean Based On A Four-way Recombinant Inbred Line Population

Improvement of seed yield of soybean(Glycine max(L.)Merr.)is generally achieved by combining morphological and yield-related traits,such as plant height(PH),node number on main stem(NN),pod number per plant(NP),seed number per plant(NS),100-seed weight(HSW)and seed weight per plant(SWPP).Identifying quantitative trait loci(QTLs)for morphological and yield-related traits is therefore important for breeding.In this study,a four-way recombinant inbred line population comprising 160 lines derived from the cross(Kenfeng14×Kenfeng15)×(Heinong48×Kenfeng19)was planted in five different environments and morphological and yield-related trait data were used to identify QTLs by the inclusive composite interval mapping method.Totally 38 QTLs for PH,40 QTLs for NN,26 QTLs for NP,10 QTLs for NS,26 QTLs for HSW and 49 QTLs for SWPP were detected in 125 genomic regions.Single QTLs explained 2.17%-14.60%,2.00%-10.04%,2.37%-9.77%,2.62%-8.61%,0.47%-6.51%and 0.14%-12.39%of the phenotypic variation for PH,NN,NP,NS,HSW and SWPP,respectively.Among these 125 genomic regions,120 were newly associated with morphological and yield-related traits.The results would facilitate the molecular breeding of morphological and yield-related traits in soybean.

Dissection of two QTL clusters underlying yield-related heterosis in the cabbage founder parent 01–20

Cabbage has significant heterosis and most commercial cultivars are hybrids.To explore genetic basis of cabbage heterosis and promote cabbage heterosis utilization,we constructed two populations by crossing 100 DH lines derived from a cabbage hybrid 01–20×96–100 with two female parents.Hybrids exhibited different extents of heterosis,the mean value of economic yield was 2.6 times bigger than parents.We identified 66 and 73 QTLs associated with mid-parent heterosis and transgressive heterosis of twelve yield-related traits,respectively.Some QTLs could be detected under the two-year experiment existed in two populations with different testers,showing relatively high phenotypic contribution rate(15.8%–20.0%).Heterosis QTLs exhibited clustered distribution in several cabbage chromosome regions.Two dominant genetic regions,mk300–316 and mk258–268,originated from the elite parent 01–20,exhibited significant genetic effects for yield-related heterosis,which were first identified.Three elite DH lines(D22,D46,D83)harboring these two dominant regions were selected as having strong heterosis in cabbage production.Candidate gene analysis revealed that some genes participating in biosynthetic processes of carbohydrates and some responses to auxin might affect cabbage yield heterosis.QTL identification and genetic dissection of yield-related traits provide new insights into the genetic effects of cabbage heterosis.

Research Progress on Genetic Breeding of Sweet Sorghum Related to Sugar Traits

Sweet sorghum is a crop with good application prospects, and the research on sweet sorghum breeding people should be strengthened. Based on this, the genetic content of QTLs(quantitative trait loci) for sugar traits in sweet sorghum was introduced, and the analysis content of the genetic breeding of sweet sorghum related to sugar traits was expounded, providing support for the cultivation of sweet sorghum with higher quality and the promotion of agricultural development in China.

Consensus linkage map construction and QTL mapping for eight yield-related traits in wheat using the BAAFS Wheat 90K SNP array

Identifying stable quantitative trait loci(QTLs)for yield-related traits across populations and environments is crucial for wheat breeding and genetic studies.Consensus maps also play important roles in wheat genetic and genomic research.In the present study,a wheat consensus map was constructed using a doubled haploid(DH)population derived from Jinghua 1×Xiaobaidongmai(JX),an F_(2)population derived from L43×Shanxibaimai(LS)and the BAAFS Wheat 90K SNP array single nucleotide polymorphism(SNP)array.A total of 44,503 SNP markers were mapped on the constructed consensus map,and they covered 5,437.92 cM across 21 chromosomes.The consensus map showed high collinearity with the individual maps and the wheat reference genome IWGSC RefSeq v2.1.Phenotypic data on eight yield-related traits were collected in the JX population,as well as the F_(2:3)and F_(2:4)populations of LS,in six,two and two environments,respectively,and those data were used for QTL analysis.Inclusive composite interval mapping(ICIM)identified 32 environmentally stable QTLs for the eight yield-related traits.Among them,four QTLs(QPH.baafs-4B,QKNS.baafs-4B,QTGW.baafs-4B,and QSL.baafs-5A.3)were detected across mapping populations and environments,and nine stable QTLs(qKL.baafs-1D,QPH.baafs-2B,QKNS.baafs-3D,QSL.baafs-3D,QKW.baafs-4B,QPH.baafs-5D,QPH.baafs-6A.1,QSL.baafs-6A,and QSL.baafs-6D)are likely to be new.The physical region of 17.25–44.91 Mb on chromosome 4B was associated with six yield-related traits,so it is an important region for wheat yield.The physical region around the dwarfing gene Rht24 contained QTLs for kernel length(KL),kernel width(KW),spike length(SL),and thousand-grain weight(TGW),which are either from a pleiotropic effect of Rht24 or closely linked loci.For the stable QTLs,254 promising candidate genes were identified.Among them,TraesCS5A03G1264300,TraesCS1B03G0624000 and TraesCS6A03G0697000 are particularly noteworthy since their homologous genes have similar functions for the corresponding traits.The constructed consensus map and the identified QTLs along with their candidate genes will facilitate the genetic dissection of wheat yield-related traits and accelerate the development of wheat cultivars with desirable plant morphology and high yield.

Major Gene Identification and Quantitative Trait Locus Mapping for YieldRelated Traits in Upland Cotton(Gossypium hirsutum L.)

Segregation analysis of the mixed genetic model of major gene plus polygene was used to identify the major genes for cotton yield-related traits using six generations P1, P2, F1, B1, B2, and F2 generated from the cross of Baimian 1 x TM-1. In addition to boll size and seed index, the major genes for the other five traits were detected： one each for seed yield, lint percentage, boll number, lint index; and two for lint yield. Quantitative trait locus/loci （QTL） mapping was performed in the F2 and F2：3 populations of above cross through molecular marker technology, and a total of 50 QTL （26 suggestive and 24 significant） for yield-related traits were detected. Four common QTL were discovered： qLP-3b（F2）/qLP-3（F2：3） and qLP-19b （F2）/qLP-19（F2：3） for lint percentage, qBN-17（F2）/qBN-17（F2：3） for boll number, and qBS-26b（F2）/qBS-26（F2：3） for boll size. Especially, qLP- 3b（Fz）/qLP-3（F2：3）, not only had LOD scores 〉3 but also exceeded the permutation threshold （5.13 and 5.29, respectively）, correspondingly explaining 23.47 and 29.55% of phenotypic variation. This QTL should be considered preferentially in marker assisted selection （MAS）. Segregation analysis and QTL mapping could mutually complement and verify, which provides a theoretical basis for genetic improvement of cotton yield-related traits by using major genes （QTL）.

3种有机物料对石灰性黑钙土及甜菜产量与品质的影响

通过研究不同有机物料对石灰性黑钙土培肥效果、甜菜产量与品质的影响,以期为在土壤培肥过程中科学选用有机物料提供理论依据。试验在田间条件下,以石灰性黑钙土栽甜菜品种H809为试验材料,设置化肥(CK)、生物有机肥(T1)、腐植化木耳菌渣(T2)、生物炭(T3)4个处理,研究了不同有机物料对耕层土壤物理性质、土壤酶活性、有机碳含量与分配及甜菜产量品质的影响。结果表明:(1)土壤容重T2和T3较CK相比显著降低了10.63%~19.02%,土壤含水量与孔隙度分别显著提高12.77%~20.74%与11.78%~21.07%;<0.25mm粒级土壤水稳性团聚体的含量各培肥处理较CK显著降低7.88%~23.29%,T1与T2处理土壤平均质量直径(MWD)、>0.25mm粒级土壤水稳性团聚体含量(R_(0.25))较CK显著增加;(2)T1、T2、T3总有机碳含量较CK提高5.17%~11.79%,各处理<0.25mm粒级土壤水稳性团聚体有机碳贡献率较CK显著降低;(3)各培肥处理蔗糖酶活性较CK显著提高30.25%~52.42%,T1与T2脲酶活性较CK显著提高27.18%~66.60%,T2与T3碱性磷酸酶活性较CK显著提高5.32%~6.11%,各培肥处理对过氧化氢酶活性无显著影响;(4)T2产量与产糖量分别较CK显著提高12.08%和13.44%。综合分析认为,腐植化木耳菌渣有机物料替代化肥可有效改善当季耕层土壤物理性质、总有机碳含量与各粒级有机碳贡献率、土壤酶活性,显著提高了甜菜产量和产糖量。

Estimating wheat spike-leaf composite indicator(SLI)dynamics by coupling spectral indices and machine learning

The contribution of spike photosynthesis to grain yield(GY)has been overlooked in the accurate spectral prediction of yield.Thus,it’s essential to construct and estimate a yield-related phenotypic trait considering spike photosynthesis.Based on field and spectral reflectance data from 19 wheat cultivars under two nitrogen fertilization conditions in two years,our objectives were to(i)construct a yield-related phenotypic trait(spike–leaf composite indicator,SLI)accounting for the contribution of the spike to photosynthesis,(ii)develop a novel spectral index(enhanced triangle vegetation index,ETVI3)sensitive to SLI,and(iii)establish and evaluate SLI estimation models by integrating spectral indices and machine learning algorithms.The results showed that SLI was sensitive to nitrogen fertilizer and wheat cultivar variation as well as a better predictor of yield than the leaf area index.ETVI3 maintained a strong correlation with SLI throughout the growth stage,whereas the correlations of other spectral indices with SLI were poor after spike emergence.Integrating spectral indices and machine learning algorithms improved the estimation accuracy of SLI,with the most accurate estimates of SLI showing coefficient of determination,root mean square error(RMSE),and relative RMSE values of 0.71,0.047,and 26.93%,respectively.These results provide new insights into the role of fruiting organs for the accurate spectral prediction of GY.This high-throughput SLI estimation approach can be applied for wheat yield prediction at whole growth stages and may be assisted with agronomical practices and variety selection.

糖用甜菜种质资源多样性分析

为探明现有国内甜菜种质资源材料和国外引进资源材料的主要农艺性状的遗传多样性,本研究对679份国内外甜菜种质资源材料的12个农艺性状进行了遗传多样性分析。结果表明,9个描述型农艺性状的遗传多样性指数在0.5876~1.4250之间。3个数值型农艺性状变异系数在33.96%~50.33%之间,其中块根产量和蔗糖含量极差最大的材料均来自中国内蒙古,块根产量变异系数最大的材料来自荷兰安地公司,蔗糖含量变异系数最大的材料来自法国。在产糖量方面,变异系数最高和极差最大的是英国莱恩公司引进的资源材料。聚类分析结果表明,679份材料可以分为4个类群,类群Ⅰ主要表现为叶丛斜立,类群Ⅱ有较高的蔗糖含量,类群Ⅲ产糖量最高,类群Ⅳ的经济类型主要表现为低产低糖型。经过种质资源鉴定和综合评价,在679份材料中鉴定出超高糖型材料6份,高糖型材料2份,丰产型材料138份,标准型材料39份,丰产兼高糖型材料1份,标准偏丰产型材料3份,标准偏高糖型材料3份,低产低糖型材料223份。

不同生态区一次性施用缓释肥在宿根蔗上的应用效果研究

为探讨不同生态区甘蔗轻简高效施肥技术,采用自主研制的甘蔗专用缓释肥,选取广西北部湾沿岸3个主要甘蔗种植区钦州市、北海市、防城港市,与当地常规甘蔗肥进行大田对比试验研究。当地常规肥采用基肥+追肥+沟施模式,缓释肥采用基肥+沟施或撒施模式。研究结果表明:与当地常规肥处理相比,甘蔗专用缓释肥处理能显著提高甘蔗有效茎数、株高和茎周长,显著提高甘蔗的锤度、蔗糖分及糖度;防城港市、北海市、钦州市3个蔗区产量分别提高了26.62%、16.54%、21.17%;经济效益分别提高了32.25%、19.83%、27.11%。综上,施用甘蔗专用缓释肥可以提高不同生态区域甘蔗的农艺性状、品质、产量及经济效益,效果显著,值得推广应用。

甜菜主要农艺性状灰色关联度分析

【目的】为了阐明不同甜菜品种主要农艺性状和品质对产糖量的影响程度,并从中筛选出适宜伊犁河谷推广种植的甜菜品种。【方法】采用方差分析和灰色关联度分析相结合的方法,对27个甜菜品种(系)农艺性状进行了综合分析。【结果】‘JTD202’产量最高(93976 kg/hm2),‘HI0064’的产量较低(93950 kg/hm2),产量前五名的品种依次为‘JTD202’>‘HJTD201’>‘BTS6870’>‘BTS5940’>‘BTS4880’;‘MA3023’含糖率最高为15.78%,‘KUHN4092’含糖率较低为12.09%,含糖率前五名的品种依次为‘MA3023’>‘BTS6870’>‘XJT9923’>‘HI0064’>‘KWS0023’。各性状对产糖量的关联度依次为含糖率>叶片数>株高>根周长>根头直径>根长>单株叶面积>块根产量,即影响甜菜产糖量的主要因素是含糖率。【结论】甜菜品种‘JTD202’、‘HJTD201’、‘BTS6870’在伊犁河谷种植表现为丰产型,甜菜品种‘MA3023’、‘BTS6870’、‘XJT9923’在伊犁河谷种植表现为高糖型,以上品种均适宜在伊犁河谷进行示范推广。

Analysis of QTLs for yield-related traits in Yuanjiang common wild rice (Oryza rufipogon Griff.)

Using an accession of common wild rice （Oryza rufipogon Griff.） collected from Yuanjiang County, Yunnan Province, China, as the donor and an elite cultivar 93-11, widely used in two-line indica hybrid rice production in China, as the recurrent parent, an advanced backcross populations were developed. Through genotyping of 187 SSR markers and investigation of six yield-related traits of two gen- erations （BC4F2 and BC4F4）, a total of 26 QTLs were detected by employing single point analysis and interval mapping in both genera-tions. Of the 26 QTLs, the alleles of 10 （38.5%） QTLs originating from O. rufipogon had shown a beneficial effect for yield-related traits in the 93-11 genetic background. In addition, five QTLs controlling yield and its components were newly identified, indicating that there are potentially novel alleles in Yuanjiang common wild rice. Three regions underling significant QTLs for several yield-related traits were detected on chromosome 1, 7 and 12. The QTL clusters were founded and corresponding agronomic traits of those QTLs showed highly significant correlation, suggesting the pleiotropism or tight linkage. Fine-mapping and cloning of these yield-related QTLs from wild rice would be helpful to elucidating molecular mechanism of rice domestication and rice breeding in the future.

Influence of Rind Hardness on Sugarcane Quality

Sugar recovery in a factory depends upon regular crushing and quality of varieties besides various other working parameters. Strategies for increased productivity and sugar recovery, varietal improvement can bring out through selection of parents to get maximum gains. These are governed by sugar content, fiber, rind hardness and cane yield. In order to assess the breeding value of different traits including rind hardness, study was undertaken at Sugarcane Research Institute, Shahjahanpur, during 2011-2012. Phenotypic difference and correlations among agronomic characters, basic quality characters and rind hardness in 120 segregating genotypes derived from contrast bi-parental cross (UP9530 × Co86011) of sugarcane cultivar were studied in this experiment. All the traits observed were found statistically significant among the mapping populations. The mean value of rind hardness was 5.91 with a range from 2.08 to 12.10 among 120 segregating population including their parents. Rind hardness (RHD) showed significant positive genotypic correlation with sugar yield-related traits viz;cane weight (CW, r = 0.325), cane yield (CYLD, r = 0.380) and sugar yield (SUYLD, r = 0.248). Significant negative correlation was observed for rind hardness with commercial cane sugar percent (CCS%, r = -0.388), number of millable cane (NMC, r = -0.216), hand refractometer brix %-October (HBR, r = -0.154), Brix% in juice (BR, r = -0.119) and Sucrose% in juice (SUC, r = -0.080). The simple correlation analysis showed that RHD, CW, CYLD and SUYLD showed significant positive correlation for agronomic characters, but for basic quality characters had negative correlations. Result indicated that rind hardness was found to have economically important trait due to showing significant positive and negative correlation with sugar yield and sugar content, respectively. The study also revealed that with the reduction in rind hardness, sugar recovery may increase. Present findings indicated that the rind hardness could play as a key role in the selection of elite genotypes in breeding program to develop high sugar, high yielding, erect, non-lodging, disease and insect resistant varieties. The details of the study were discussed in the manuscript.

Effect of Salinity and Potassium Enrichment on Some Growth Attributes in Sugar Beet (Beta vulgaris L.)

A pot experiment was conducted during winter growing season of 2014 at Homs Agriculture Research Center, General Commission for Scientific Researches (GCSAR), Syria. A factorial experiment arranged according to complete randomized block design with six replications was used. A combination of four levels of saline irrigation water (tap water, 2,000, 4,000 and 6,000 ppm), with three K levels (180, 360 and 540 ppm), was used to evaluate the effects of saline irrigation water and K enrichment on some growth attributes of two sugar beet varieties (Semper and Alligator). Results showed that all studied growth attributes, i.e., leaf area (LA), leaf number (LN), total dry matter (TDM) and net assimilation rate (NAR) were decreased under salinity stress conditions compared to the control, while K enrichment significantly increased some of the studied characters such as LA, TDM and NAR, but the differences in LN were apparent according to increase in K levels. The variety Semper surpassed significantly the variety Alligator in LA, TDM and NAR. Results also indicated a significant interaction between salinity×potassium enrichment, varieties×potassium enrichment and salinity ? varieties.

氮肥施用量对甜玉米‘申科甜811’农艺性状及可溶性糖含量的影响

以甜玉米品种‘申科甜811’为试验材料,设置5个氮肥施用量处理(0、100、200、300、400 kg∕hm^(2)),研究氮肥施用量对其农艺性状及可溶性糖含量的影响。结果表明:甜玉米‘申科甜811’株高、穗位高、双穗率、穗重和穗长等农艺性状与氮肥施用量存在显著的正响应关系。穗重受氮肥施用量的影响最为明显,其以有限指数增长的模式响应氮肥施用量的增加,当氮肥施用量小于100 kg∕hm^(2)时,穗重对氮肥的正响应程度较高,当氮肥施用量大于100 kg∕hm^(2)时,穗重对氮肥的正响应程度显著降低。氮肥施用量在100—200 kg∕hm^(2)时可以显著提高甜玉米‘申科甜811’株高、穗位高、双穗率、穗重和穗长,并有效降低空秆率和秃尖长度,增加籽粒中可溶性糖含量,提高甜玉米的产量和商品性。