基于层次分析法和GGE双标图对引进马铃薯种质资源的综合评价

基于层次分析法和GGE双标图法对引进于国际马铃薯中心的97份马铃薯种质资源的主要农艺性状以及适应性、稳定性、丰产性等方面进行综合分析,筛选与鉴定优良可利用种质资源,同时为构建马铃薯种质资源的综合评价体系提供理论依据。结果表明,农艺性状、产量性状和品质性状所占权重大小为0.075、0.70和0.23,其中农艺性状中株高和茎粗所占权重为0.38和0.29,产量性状中产量权重为0.73,品质性状中干物质含量和蛋白质含量权重分别为0.4和0.2。C77和C51适合在甘肃省白银市景泰地区推广种植,C116、C89、C27、C66和C98在甘肃省定西市地区适应性强;参试品系稳定性大小为C49>C46>C116>C112>C93;丰产性为C89>C116>C93>C97>C112>C49>C46>C67。层次分析法与GGE双标图综合分析可知:C46、C49、C112、C116综合表现较好,可以作为优良品系参加品种审定试验,也可以作为亲本材料。层次分析法和GGE双标图相结合可以作为引进马铃薯种质资源综合评价体系的标准。

Agronomic Performance, Stability Analysis and Evaluation of Anthracnose Disease Resistance of Common Bean Lines Derived by Marker-Assisted Backcrossing in Uganda

The present study focused on evaluating the agronomic performance, stability, and anthracnose resistance of common bean lines derived through Marker-Assisted Backcrossing in Uganda. Eight marker-assisted selection (MAS) backcross-derived bush bean lines with red seed types, alongside two checks, were evaluated in a randomized complete block design replicated two times in five locations for three consecutive crop-growing seasons in 2021 and 2022. The study aimed to identify lines with both high stable yields and enhanced resistance to anthracnose disease for potential release and utilization in future bean varietal development in Uganda. Agronomic traits, including days to 50% flowering, days to 90% physiological maturity, seed yield, seed yield components, and anthracnose disease reaction under natural infestation were assessed. The response to anthracnose disease was further assessed using six isolates of Colletotrichum lindemuthianum representing six different races. Results indicated that the agronomic performances of the MAS backcross-derived bush bean lines were statistically comparable to the recurrent parent NABE14. Specifically, six lines exhibited statistically equal to or higher performance than NABE14 in terms of seed yield, total number of seeds and number of pods per plant. The combined analysis of variance for seed yield showed significant (p Co-42 and Co-5 anthracnose resistance genes in the derived line. In conclusion, UGKT-B157-4, identified as the best-performing and stable genotype, demonstrates promise for release and use in future bean varietal development in Uganda, offering a combination of high yields and enhanced anthracnose disease resistance. The study provides valuable insights into the potential of Marker-Assisted Backcrossing in improving common bean varieties in the region.

The Application of GGE Biplot Analysis for Evaluating Test Locations and Mega-Environment Investigation of Cotton Regional Trials

In the process to the marketing of cultivars, identification of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to governmental organizations in charge of cultivar registration. Where competition among breeding companies exists, effective and fair multi-environment variety trials are of utmost importance to motivate investment in breeding. The objective of this study was to use genotype main effect plus genotype by environment interaction（GGE） biplot analysis to evaluate test locations in terms of discrimination ability, representativeness and desirability, and to investigate the presence of multiple mega-environments in cotton production in the Yangtze River Valley（YaRV）, China. Four traits（cotton lint yield, fiber length, lint breaking tenacity, micronaire） and two composite selection indices were considered. It was found that the assumption of a single mega-environment in the YaRV for cotton production does not hold. The YaRV consists of three cotton mega-environments： a main one represented by 11 locations and two minor ones represented by two test locations each. This demands that the strategy of cotton variety registration or recommendation must be adjusted. GGE biplot analysis has also led to the identification of test location superior for cotton variety evaluation. Although test location desirable for selecting different traits varied greatly, Jinzhou, Hubei Province, China, was found to be desirable for selecting for all traits considered while Jianyang, Sichuan Province, China, was found to be desirable for none.

GGE biplot analysis of yield stability and test location representativeness in proso millet (Panicum miliaceum L.) genotypes

The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were to analyze yield stability and adaptability of proso millets and to evaluate the discrimination and representativeness of locations by analysis of vari- ance （ANOVA） and genotype and genotype by environment interaction （GGE） biplot methods. Grain yields of proso millet genotypes were significantly influenced by environment （E）, genotype （G） and their interaction （GxE） （P〈0.1%）. GxE inter- action effect was six times higher than G effect in non-waxy group and seven times in waxy group. N04-339 in non-waxy and Neimi 6 （NM6） in waxy showed higher grain yields and stability compared with other genotypes. Also, Neimi 9 （NM9, a non-waxy cultivar） and 90322-2-33 （a waxy cultivar） showed higher adaptability in 7 and in 11 locations, respectively. For non-waxy, Dalat, Inner Mongolia （E2） and Wuzhai, Shanxi （E5） were the best sites among all the locations for maximizing the variance among candidate cultivars, and Yanchi, Ningxia （El0） had the best representativeness. Wuzhai, Shanxi （e9） and Yanchi, Ningxia （e14） were the best representative locations, and Baicheng, Jilin （e2） was better discriminating location than others for waxy genotypes. Based on our results, El0 and e14 have enhanced efficiency and accuracy for non-waxy genotypes and waxy genotypes selection, respectively in national regional test of proso millet varieties.

One compound approach combining factor-analytic model with AMMI and GGE biplot to improve multi-environment trials analysis

To improve multi-environmental trial(MET)analysis,a compound method—which combines factor analytic(FA)model with additive main effect and multiplicative interaction(AMMI)and genotype main effect plus genotype-by-environment interaction(GGE)biplot—was conducted in this study.The diameter at breast height of 36 open-pollinated(OP)families of Pinus taeda at six sites in South China was used as a raw dataset.The best linear unbiased prediction(BLUP)data of all individual trees in each site was obtained by fitting the spatial effects with the FA method from raw data.The raw data and BLUP data were analyzed and compared by using the AMMI and GGE biplot.BLUP results showed that the six sites were heterogeneous and spatial variation could be effectively fitted by spatial analysis with the FA method.AMMI analysis identified that two datasets had highly significant effects on the site,family,and their interactions,while BLUP data had a smaller residual error,but higher variation explaining ability and more credible stability than raw data.GGE biplot results revealed that raw data and BLUP data had different results in mega-environment delineation,test-environment evaluation,and genotype evaluation.In addition,BLUP data results were more reasonable due to the stronger analytical ability of the first two principal components.Our study suggests that the compound method combing the FA method with the AMMI and GGE biplot could improve the analysis result of MET data in Pinus teada as it was more reliable than direct AMMI and GGE biplot analysis on raw data.

Cultivar Selection and Test Site Evaluation of Cotton Regional Trials in Jiangsu Province Based on GGE Biplot

This study was to evaluate the high yielding and stability of candidate cultivars, depict the adaptive planting region, analyze trial location discrim-ination ability and representativeness, as wel as identify the ideal cultivar and trial location, with the aim to provide theory background for cultivar selection and rea-sonable scheme of test location in Jiangsu Province. [Method] The GGE biplot method was used to analyze the lint cotton yield of 12 experimental genotypes in the 6 test locations （three replicates in each） of the cotton regional trial in Jiangsu Province in 2013. [Result] The effects of genotype （G）, environment （E）, and geno-type by environment interaction （G＆#215;E） on lint cotton yield were al highly significant （P〈0.01）, which made it necessary to further explore the specific pattern of geno-type by environment interaction. Jinmian118 （G4） and SF3303 （G5） were the best ideal genotypes screened by the ＂ideal cultivar＂ and ＂ideal location＂ view of GGE biplot, and the ordination of test sites based on the ideal index were in the order of Dafeng （DF）, Yanliang （YL）, Liuhe （LH）, Dongtai （DT）, Yancheng （YC）, and Nantong （NT）, among which NT was relatively weak in representing of the whole target cot-ton planting region in Jiangsu Province. The ＂similarity among locations＂ view of GGE biplot clustered al trial locations into one group, showing that the test sites in the cotton planting region in Jiangsu Province were in the same mega-environment. The ＂which-won-where＂ view of GGE biplot indicated that cotton cultivar Jinmian118 （G4） was the most appropriate cultivar in the homogeneous cotton planting region in Jiangsu Province. [Conclusion] Among the candidate cultivars, Jinmian118 and SF3303 were identified as the most ideal cultivars in this set of conventional cotton regional trial in Jiangsu Province; the test site of Dafeng ranked the first out of al locations in terms of discrimination and representativeness, and al test locations were clustered into the same mega-environmet, which indicated the high efficiency of cultivar selection in the cotton regional trial in Jiangsu Province.

Perform Stability of Isoflavones of Soybean Cultivar Evaluated by Genotype-genotype×environment(GGE) Biplot

As one of the secondary metabolites,the isoflavones formed during the development of soybean[Glycine max(L.)Merr.]seeds.The total and individual isoflavone contents,a typical quantitative trait,were affected by significant genotypes of environments(GE)interaction and controlled by many genes with main or minor effects.In the present study,99 soybean cultivars,collected from northeastern China,were used to analyze the isoflavone performances.Genotype-genotype×environment(GGE)biplot software demonstrated an ability to provide information on genetic main effects than solely on phenotypic perform.Highperformance liquid chromatography(HPLC)system was used to extract and determine the isoflavone contents.The results indicated that most genotypes significantly varied among six tested environments.P40(Xiaolimoshidou)was the best-performed genotype with mean performance and stability for glycitein content across six different environments.P88(L-59Peking)was the super genotype with mean performance and stability on each tested environment for daidzein,genistein and the total isoflavone.E5(Gongzhuling in 2016)was the best environment for optimal environmental factor mining.P70(Charleston),P67(Baichengmoshidou)and P50(Jiunong 20)were the optimal genotypes with the highest field among 99 cultivars on each tested environment for genistein.P70(Charleston),P67(Baichengmoshidou)and P14(Hefeng 25)were the optimal genotypes with the highest field among 99 cultivars on each tested environment for daidzein.P40(Xiaolimoshidou),P45(Jinshanchamodou),P33(Dongnong 48)and P56(L-5)were the optimal genotypes with the highest field among 99 cultivars on each tested environment for glycitein.P70(Charleston)and P67(Baichengmoshidou)were the optimal genotypes with the highest field among 99 cultivars on each tested environment for the total isoflavone.GGE biplot was a rational method for stability and adaptation evaluation of soybean isoflavones,and could assist soybean breeder to select a good culture and a suitable tested site.It provided a scientific basis for the establishment of a breeding site and a selection site of soybean isoflavones.This study was valuable to identify genotypes with stable performances of isoflavones of these 99 cultivars for developing new cultivars.

Multi-environmental Evaluation of Triticale, Wheat and Barley Genotypes by GGE Biplot Analysis

The research was carried out with 9 triticale, 3 bread wheat, 3 durum wheat and 3 barley varieties and advanced lines in Tekirdag, Edime and Silivri locations during three years. In the study, the data obtained from combined variance analysis were performed and the significance of the differences between the averages was determined by LSD multiple comparison test. GGE biplot analysis and graphics were made by using the statistical package program. The genotypes G2 and G3 for thousand kernel weight, genotype G1 for the heading time and test weight, genotypes G14 and G15 for the maturation time, number of spikelets per spike and grain weight per spike and G13 for the plant height, spike length and grain yield per hectare decare revealed the highest values. The genotypes G6, GS, G4, G14, G9, G8 and G7 gave lower values than the average in terms of grain yield, whereas the other genotypes gave higher values than the general average. According to biplot graphical results, while locations 1 and 8 were closely related, locations 9, 2 and 7 were positively related to these environments. Although the location 7 is slightly different from the other 4 locations, these 5 locations can be seen as a mega environment. Genotypes G12, G2, G3 and G10 for this mega-environment showed the best performances. According to the results of grain yields obtained from 9 different locations, the location 5 was the most discriminating area while the location 1 was the least discriminating. Location 2 was the best representative location, while locations 4 and 7 were with the lowest representation capability. The locations that are both descriptive and representative are good test locations for the selection of adapted genotypes. Test environments, such as location 8, with low ability to represent are useful for selecting genotypes that perform well in specific regions if the target environments can be subdivided into sub-environments.

Family selection and evaluation of Larix gmelinii var.principis-rupprechtii(Mayr.)Pilger based on stem analysis data at multiple sites

Larix gmelinii var.principis-rupprechtii(Mayr.)Pilger is an important native tree species in North China with advantages of fast growth,straight trunk,and good wood properties.The multi-year and multi-site breeding research of families of the species has not been reported previously.Based on diameter at breast height(DBH),height and volume of 25 families on four experimental sites,we calculated variance components,genetic parameters,juvenile and mature trait correlations and made genotype main effect plus genotype×environment interaction effect(GGE)biplot based on the breeding values estimated using the method of best linear unbiased prediction(BLUP).Compared with height,DBH and volume had higher heritability and larger variation coefficients,making them the more suitable traits for family selection and evaluation.Based on these,GGE biplots containing 20 combinations of site×age were drawn using data at 13 to 17 years when the interactions between family and location were strong.Test sites classifications based on DBH,and volume were inconsistent,with two categories for DBH and one for volume.The Guyuan site was the most suitable with strong discriminating ability,high representativeness and stability among tree ages.Integrating the ranking results of DBH and volume,families 66,76,82 and 111 were high-yielding and stable,families 78 and96 were high-yielding with above average stability,families72 and 79 were high-yielding with below average stability,whereas stability of family 100 was inconsistent between DBH and volume.Early selection based on DBH was convenient and reliable,and can be made at seven years.This study provides support for the selection of Larix gmelinii var.principis-rupprechtii families in Hebei province and an example for the application of stem analysis data from multiple sites in tree breeding.

Variation and stability analysis of growth traits of poplar clones in the seedling stage in northeast China

Plant phenotypes are infl uenced by genetic and environmental factors.In this study,the growth traits of 43 one-year-old poplar clones grown at diff erent sites in northeast China(Dongling State-owned Forest Protection Center,DL;Baicheng State-owned forest farm,BC;and Cuohai Forest farm,CH)were evaluated and analyzed across clones and sites.Results show signifi cant diff erences in height and base diameter among sites and clones.Phenotypic and genetic variation coeffi cients ranged from 49.59%(BC)to 58.39%(DL)and from 49.33%(BC)to 58.06%(DL),respectively.Additive main eff ects and multiplicative interaction(AMMI)analysis showed that the eff ects of genotype,environment,and genotype×environment interaction were signifi cantly diff erent.Genetic variation was the main source of variation,accounting for 48.6%.AMMI biplot showed that clone 30 had high and stable yields at the three sites.From an evaluation of multiple traits and GGE biplot that clone 2,clone 30 and clone 25 had higher yield than the other clones at DL,CH and BC,respectively.These clones will provide material for forest regeneration in northeast China.

Improvement of Early Maturing and Climate Resilient Chickpea (Cicer arietinum L.) Cultivars Suitable for Multiple Environments in Bangladesh

Ensuring food security for the rapidly increasing population and changing climatic scenarios are requisites for exploiting the genetic divergence of food crops.A study was undertaken to sort out an early maturing chickpea variety for fitting easily between rice-rice cropping systems in the Eastern Indo-Gangetic Plain of Bangladesh.The trial was comprised of eight elite lines of chickpea and executed at various localities in Bangladesh from 2014–15 to 2017–18.The result explored the chickpea genotype,BARI Chola-11 remained superior to the rest of the elite genotypes for having a short maturity period(100–106 days),and lesser days to 50%flowering(47–55 days).The same genotype was recorded to have robust vegetative and reproductive yield attributes including plant height(49–57 cm),podsplant−1(37–50),and optimum 100 seed weight(19.5–20.6 g).Owing to better yield attributes,BARI Chola-11 resulted in the maximum seed yield(1200–1500 kg ha-1)of chickpea and might be recommended for general adoption in the region for boosting nutritional security status through improved productivity under changing climate.

应用多元统计分析玉米农艺性状

在作物遗传育种研究中,产量及其相关性状多属于数量性状范畴,这类性状由多基因控制,易受环境影响使其遗传极为复杂,并且性状间常存在复杂相关关系。产量及其相关性状间的复杂关系使得育种中对以产量为目标的选择极为困难。多元统计分析是研究客观事物中多个变量之间相互依赖的统计规律性综合分析方法。合理利用多元统计分析可以加深对性状间相互关系的遗传规律及各相关性状对产量影响的主次和依存关系认识,为新品种选育和改良提供理论依据。对35个玉米品种(组合)的20个农艺性状应用GGE双标图、因子分析和聚类分析研究,结果表明,平均日产量、千粒重、穗长与产量呈显著正相关;20个农艺性状可综合为6个公因子;以6个公因子为综合指标对35个品种(组合)聚类结果聚成17个类群,其中G8、G14、G12、G10和G17为综合性状优良品种(组合)。

Evolution of Main Characteristics of the Registered Cotton Cultivars in National Cotton Regional Trials in Yangtze River Valley

[Objective] The aim of this study was to characterize the national regis- tered varieties selected from cotton regional trials in Yangtze River Valley （YaRV） in recent years. [Method] Cotton cultivar classification and comprehensive evaluation index were set up based on national cotton registration standard. GGE biplot method was adopted to analyze the correlation of major breeding target characters of 53 national registered cotton varieties in cotton regional trials in YaRV during 1981-2012. According to the shift of check cultivars in cotton regional trials in the past, the cotton regional trial practice since 1981 was divided into five periods. The dynamic of cultivar type＇s proportion and the evaluation index scores was analyzed across the five periods. [Result] There existed intricate interrelationship among cotton breeding target traits, which constrained it necessary to construct indices for com- prehensive evaluation of cotton varieties. The dynamic of cultivar types in the five periods indicated that type II varieties emerged since Simian 3 period and then its proportion decreased gradually; type Ⅲ varieties maintained a certain proportion in each period and kept on the rise overall; type Ⅳvarieties occupied the majority pro- portion of registered cultivars before 1993, but a minor proportion since Simian 3 period. On the other side, the change trend of the evaluation index demonstrated that the varieties registered before 2003 did not pass the qualified line at present. The peak scores appeared in the varieties registered during 2004-2008. The scores of the varieties registered after 2009 were only slightly over the qualified line. [Conclusion] More attention should be paid to the improvement and evaluation of micronaire, so as to guide the simultaneous development of high yielding and fiber quality in cotton breeding and registration procedure in YaRV.

Genotype×year interaction of pod and seed mass and stability of Pongamia pinnata families in a semi-arid region

Sixteen pongamia families were evaluated in a field experiment for eight consecutive years in dryland conditions to identify stable,high-yielding families.The trial was conducted in a randomized complete block design with three replications.Each family,consisting of nine trees per replication,was planted at a spacing of3 m x 3 m.Yield stability was analyzed using(1)Eberhart and Russel’s regression coefficient(β_i)and deviation from regression(S_d^2),(2)Wrike’s ecovalence(W_i);(3)Shukla stability variance(σ_i^2);and(4)Piepho and Lotito’s stability index(L_i).Families were also analyzed for adaptability and stability using AMMI and GGE biplots graphical methods.The study revealed significant variances due to family and family x year interaction for pod and seed yield.Families performed differently and ranked differently across years.The performance of families was influenced by both genetic factor and environmental conditions in different years.Among families tested,TNMP20,Acc14,TNMP14 and Acc30 were high yielders for pods,and Acc14,Acc30,TNMP6,RAK19 and TNMP14 were high for seed yield.According to the Eberhart and Russell model,Acc30,TNMP14 and TNMP3 were stable across years.In the graphical view of family x year interaction based on AMMI methods,TNMP3,TNMP4 and TNMP14 had greater stability with moderate seed yield,and Acc14 and Acc30 had moderate stability with high seed yield.On the other hand,GGE biplots revealed Acc14,Acc30 and TNMP14 as high yielders with moderate stability.AMMI and GGE biplots were able to capture nonlinear parts of the family x year interaction that were not be captured by the Eberhart and Russel model while also identifying stable families.Based on different methodologies,Acc14,Acc30 and TNMP14 were identified as high yielding and stable families for promoting pongamia cultivation as a biofuel crop for semi-arid regions.

Genotype-by-environment interaction for grain yield among novel cowpea(Vigna unguiculata L.) selections derived by gamma irradiation

This study determined the effects of genotype-by-environment(G × E) interaction and stability of yield among elite cowpea(Vigna unguiculata L.) selections derived by gamma irradiation. The study was conducted in Namibia at three selected sites: Bagani, Mannheim,and Omahenene, during 2014/2015 and 2015/2016. Thirty-four newly developed mutant genotypes and three local checks were evaluated using a randomized complete block design with three replications. Grain yield data were analyzed using the additive main effects and multiplicative interaction(AMMI) and the genotype main effect plus genotype-by-environment interaction(GGE) biplot methods. The AMMI and GGE biplot models explained 77.49% and 75.57% of total observed genotypic variation, respectively.Bagani and Omahenene were the environments best discriminating the test genotypes during 2014/2015 and 2015/2016, respectively. Four promising mutant genotypes: G9(Sh L3 P74), G10(Sh R3 P4), G12(Sh R9 P5), and G4(Sh L2 P4), showed wide adaptation and grain yields of 2.83, 2.06, 1.99, and 1.95 t ha^(-1), respectively. The novel mutant lines are useful genetic resources for production or future cowpea breeding programs in Namibia or similar environments.

Evaluation of yield,stability and adaptability of national winter rapeseed regional trials in the upper Yangtze River region in 2017-2018

Rapeseed variety needs to be tested by regional trial in multiple sites for many years before being applied in market in China.Performants of rapeseed were affected by the interaction of sites and varieties.Evaluation of regional trials is very important for guiding rapeseed breeding.GGE(genotype main effects and genotypeenvironment interaction)biplot was used to evaluate yield,stability,adaptability,representativeness and discrimination of national winter rapeseed trials in the upper reaches of Yangtze River in 2017-2018.Results showed that the main effects of genotype(G),environment(E)and genotypeenvironment interaction(GE)were significant(P<0.01)for yield.Among them,E accounted for 46.95%total variation on average,G and GE accounted for 19.34%and 33.71%respectively.Eight varieties were found with high-yield,excellent stability and adaptability,including‘Yiyou 29’,‘Xiwang 920’,‘Liyouza 108’,‘Nanyou 546’,‘Dadi 195’,‘Jiayou 1’,‘Huayouza 28’and‘Yuhua 2’.Test sites included Nanchong,Mianyang,Wanzhou,Shuangliu and Chengdu in Sichuan Province and Zunyi together with Guiyang in Guizhou Province were selected for their excellent representativeness and discrimination.These results would provide theoretical basis for rapeseed breeding.

Evaluation on the High Yielding, Stability and Comprehensive Performances of Check Cultivars in National Cotton Regional Trials in the Yangtze River Valley

[Objective] This study was to analyze the high yielding, stability, adaptabil-ity and main characteristics of check cultivars in national cotton regional trials in the Yangtze River Val ey in 2000-2013, with the aim to provide theoretical basis for the reasonable selection of check cultivars for cotton regional trials. [Method] GGE biplot analysis method was used to carry out the intensive analysis and comprehensive comparisons on the performances and differences of the 9 major characters of check cultivars, namely, lint cotton yield , stability, and other main traits including bol weight, bol number, lint percentage, fiber length, fiber strength, micronaire val-ue, plant height and seed index. [Result] Ezamian 10 was suitable in the majority of cotton planting regions in the Yangtze River Val ey, with the best high yielding abili-ty and perfect yield stability. The yielding ability of Xiangzamian 8 ranked the sec-ond, but its stability was the poorest. Xiangzamian 8 was of the specific adaptive cultivar with relatively good performance in high yielding but the poorest stability. The suitable planting areas of Xiangzamian 8 were limited to the cotton planting re-gion around Dongting Lake in Hunan province, Poyang Lake in Jiangxi Province, the Coastal region in Jiangsu Province and Wuhan district in Hubei Province. Xi-angzamian 2 performanced poorer in both yielding and stability, while Simian 3 ranked first in stability but the last in yielding ability. The dominant character of Xi-angzamian 8 and Xiangzamian 2 were high cotton plants and big bol s. Simian 3 performanced super in lint percentage and fiber length. Ezamian 10 was strong in cotton bol formation ability, lint cotton yielding, fiber strength and seed size, as wel as high micronaire value. [Conclusion] The outstanding performance of Ezamian 10 in high and stable yield in the Yangtze River Val ey in recent years has effectively promoted the high yielding ability of candidate varieties in cotton regional trials in the area.

Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and Its Influences on Cotton Yield in the Yangtze River Valley

[Objective] The historical evolution pattern of nitrogen （N）, phosphorus （P） and potassium （K） fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.

Modelling Causes of Temporal Genotype-By-Environment Interaction in Oil Palm Bunch Yield in Nigeria

The objectives of this research were to understand pattern of temporal （year to year） stability in oil palm genotypes and then identify weather variable（s） associated with temporal stability. Stability analysis was performed using the GGE biplot method. The best genotype in one year was not same always in the other year due to changes in the weather conditions over the years. Test environment evaluation revealed that the year 2000 （Y00） was the best representative of the overall environments and most powerful to discriminate genotypes with superior mean yield and temporal stability. The relationship of the climatic factors on the basis of their joint contribution to the development of specific trait varied from the pattern observed when their roles on the same traits were individually assessed. Maximum relative humidity, sunshine and rainfall could help explain the yield fluctuation due to their contribution to the overall yield variation. However, genotypes GI0 and G2 which exhibited high mean performance and stability for BN would be beneficial to the oil palm growers in ensuring steady cash flow from regular bunch yield production.