Efficiency of secondary traits in selecting for improved grain yield in extra‐early maize under Striga‐infested and Striga‐free environments

A base index involving Striga damage, number of emerged Striga plants and ears per plant is used for selecting for maize (Zea mays L.) grain yield under Striga infestation. There are contradictory reports on the reliability of number of emerged Striga plants for selecting for Striga resistance. The objective of this study was to confirm reliability of the secondary traits for selecting for improved grain yield under Striga infestation. Ten Striga‐resistant extra‐early cultivars were evaluated for 3 years under artificial Striga‐infested and Striga‐free environments in Nigeria. Analysis of variance combined across years and locations showed significant mean squares for genotype, year, location and their interactions for most traits. Sequential path analysis identified ear aspect as the only trait with significant direct effect on yield under artificial Striga infestation, while GGE biplot confirmed ear aspect, ears per plant and Striga damage as the most reliable traits. Ear aspect should be included in the base index for selecting for improved grain yield of extra‐early maize under Striga infestation, while the number of emerged Striga plants should be excluded.     

The Application of GGE Biplot Analysis for Evaluat ng 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.     

我国主产棉区棉花纤维品质性状的区域分布特征

我国主产棉区及其亚区的棉纤维品质区域特征明显,适时评价各棉区的纤维品质发展现状有助于稳定优势棉花产区和促进特色棉花产区的发展。本研究采用GGE双标图分析了2011—2015年全国棉花品种区域试验中各亚区环境与纤维品质性状的互作模式,分析比较了各主产棉区和亚区的纤维品质特征。结果表明:1)在主产棉区尺度上,长江流域棉区纤维长度和比强度最好,并且都达到了国家棉花品种审定的Ⅱ级标准,而马克隆值和纺纱均匀性指数居中;黄河流域棉区的纤维长度和比强度较好,但马克隆值偏高;西北内陆棉区的马克隆值和纺纱均匀性指数表现最好,纤维长度和马克隆值达到了国家棉花品种审定的Ⅱ级标准,但比强度在三大棉区中表现最差。2)在棉花亚区尺度上,纤维长度表现以长江下游和长江上游亚区为最好,黄土高原亚区稍差,其余亚区表现较好;比强度表现以长江下游、长江中游、淮北平原、南襄盆地和黄土高原最好,而南疆棉区、长江上游和北疆棉区比强度稍差;马克隆值以北疆棉区、南疆棉区和长江上游表现最好,而黄土高原、淮北平原、长江中游和华北平原的马克隆值偏高。3)在纤维品质的综合表现上,北疆棉区、长江下游、长江上游和南疆棉区的纤维品质综合表现最好,淮北平原、长江中游和南襄盆地次之,华北平原和黄土高原稍差。本研究展示了GGE双标图的"环境?性状"功能图在纤维品质区域特征评价方面的应用效果,可为我国棉花优势产区发展和棉纺企业合理用棉提供理论依据,也对全国棉花纤维品质生态区划分具有指导意义。     

甘肃省多点联合试验马铃薯产量要素稳定性及试点鉴别力分析

为全面评价甘肃省马铃薯品种多点联合试验中参试品种（系）产量要素性状在不同环境中的丰产性、稳定性、适应性和各试点的代表性、鉴别力,利用R语言的GGEBiplot GUI程序包对参加2017-2018年甘肃省马铃薯品种多点联合试验的8个参试品种（系）‘L1036-34’（P1）、‘F80’（P2）、‘201106-7’（P3）、‘D0602-10’（P4）、‘天11-8-2’（P5）、‘天11-8-24’（P6）、‘西和蓝’（P7）和‘陇薯6号’（P8）在6个试点的产量要素性状进行双标图分析。结果表明,在两年6个试点中小区产量适应性、丰产性、稳产性最强的参试品系均为P1;商品薯丰产性、稳产性较好的品系为P1、P5;单株产量丰产性、稳产性较好的品系为P1、P5;单株结薯数丰产性较好的品系为P2、P1,稳定性好的品系为P1、P5;商品率丰产性、稳产性较好的品系为P6。综合产量要素分析,参试品种（系）的丰产性、稳定性和适应性的综合排序依次为P1、P5、P6、P2、P4、P8、P7、P3。双标图能够简单直观有效的评价参试品系和试点,较为理想的品系为P1,较为理想的试点为会川、天水、临夏。     

应用AMMI模型评价马铃薯品种的稳定性和适应性

应用AMMI模型对6个马铃薯品种的区试产量进行了分析。结果表明:在线型回归分析的条件不具备时,AMMI模型可解释基因型与环境之间的互作。通过AMMI模型双标图和稳定性参数可以比较基因型与环境互作的大小,进而评价各参试品种的稳定性与适应性。     

Biplot Analysis of Genotype by Environment for Cooking Quality in Hybrid Rice： A Tool for Line x Tester Data

A study of combining ability for improving rice cooking quality was carried out via genotype plus genotype x environment （GGE） biplot. Four restorer lines and three male sterile lines were used to obtain F1 in a line x tester trial at the Rice Research Institute, Amol, Iran in 2009. GGE biplot analysis showed that Neda and IR56 were the best general combiners for amylose content （AC）, whereas Nemat and IR28 had the highest general combining ability （GCA） effects for gelatinization temperature （GT）, and IR58 and IR59 showed the highest GCA effects in terms of gel consistency （GC）. Meanwhile IR58 and IR59 showed large specific combining ability （SCA） effects for AC, while Neda and SA13 had high SCA effects for GT. Nemat and IR28 had large SCA effects for GC. Because intermediate levels ofAC, GT and GC are ideal, Nemat × IR59 was considered as the best possible cross. Based on these results, the GGE biplot showed good potential for identifying suitable parents, heterotic crosses and the best hybrids in line x tester data.     

种植密度和施氮量对玉米‘伊单52’和‘伊单81’产量的影响

为蒙西地区玉米栽培及试验数据分析评价提供参考,以玉米品种‘伊单52’和‘伊单81’为试验材料,进行大田试验。应用GGE双标图法分析研究3 个氮肥水平和5 个密度水平下玉米产量、叶面积指数、干物质变化。结果表明在A2 氮肥水平下,‘伊单52’叶面积指数高于A1 和A3 氮肥水平,‘伊单52’和‘伊单81’群体干物质积累量最高。‘伊单52’和‘伊单81’在5 个密度、3 个肥料水平下的产量、叶面积指数、群体干物质重GGE双标图中,分别展示了各处理真实信息的82.3%和70.7%。     

龙岩适应性烤烟品种(系)评价筛选

为准确、客观地筛选出适宜龙岩烟区种植的优良烤烟品种（系）,联用方差分析、AMMI模型和GGE双标图3种方法对‘闽烟35’、‘C2’、‘FL88f’、‘翠碧1号’、‘闽烟38’、‘闽烟57’、‘F31-2’、‘FL25’和‘云烟87’等9个烤烟品种（系）连续2年的经济性状和品质性状的多目标决策值进行分析评价。结果表明,龙岩烤烟品种（系）的经济、品质性状表现主要受品种效应影响,其次是品种×地点互作效应。其中,‘FL88f’经济性状丰产性表现最好,显著优于‘云烟87’,稳定性较好且适应性强;品质性状的丰产性、稳定性和适应性均较好,稍优于‘云烟87’。因此,综合经济性状和品质性状表现,品系‘FL88f’可以作为龙岩烟区的后备品系,建议审定后应用。     

冬播春性小麦产量相关性状与抗旱性的关系研究

为明确春小麦产量相关性状与抗旱性的关系,以CIMMYT提供的28份春小麦品系为试材,在雨养及灌溉条件下,对主穗小穗数、穗粒数、不孕小穗数、千粒重、收获指数和小区产量等性状进行考察,分析春小麦主要产量相关性状的遗传力,评价春小麦品系的抗旱性,用GGE双标图对产量相关性状与抗旱性的遗传相关进行分析。结果表明:春小麦的抗旱性与多种产量性状相关;2种水分条件下主穗小穗数、穗粒数、千粒重和小区产量的遗传力较大(42.79%~78.87%)。不同水分条件下主要产量相关性状与抗旱性的遗传相关程度存在差异。通过对产量相关性状的遗传相关系数及遗传力进行联合分析,可以看出在雨养条件下主穗小穗数、穗粒数和小区产量对春小麦抗旱性的选择效率较高,在春小麦抗旱育种中应当注重对这些产量相关性状进行考察及选择。     

一年两季鲜食糯玉米区域试验的GGE双标图分析

[目的]综合评价广西一年两季鲜食糯玉米区域试验品种基因型及基因型与环境互作的关系,为玉米区域试验和育种工作提供参考.[方法]应用GGE-biplot对广西2016年春季和秋季鲜食糯玉米区域试验的鲜穗产量进行GGE双标图分析,评价参试玉米品种的丰产性、稳产性和适应区域,以及各承试点的代表性和鉴别力.[结果]参试玉米品种与环境的综合评价分析结果表明,多数试点间存在正相关,其中春季试验北海和玉林及秋季试验北海和柳州试点间存在紧密正相关,对品种产量排序的影响相似.参试玉米品种适宜环境的分析结果表明,春季7个试点可分为4个生态区,秋季7个试点可分为3个生态区,直观展示了品种的适应性.参试品种丰产性和稳定性的分析结果显示,春季品种桂W1518和秋季品种百香糯1601在当季具有较好的丰产性和稳定性.环境鉴别力与代表性分析结果表明,春季柳州和南宁试点为较理想的试验环境,秋季玉林和河池试点为较理想的试验环境.[结论]GGE双标图直观展示了参试玉米品种的丰产性、稳产性和适应性,以及承试环境的鉴别力、代表性和生态类型,对玉米区域试验和育种工作具有重要参考价值.