为筛选出适合崇左蔗区生态环境的甘蔗新品种,国家糖料产业技术体系在 2019～2021 年组织开展了第 6轮联合区域试验.通过开展田间试验,比较分析参试的 10 个甘蔗品种 1 年新植蔗和 2年宿根蔗的主要农艺性状、产量、蔗糖分、含糖量、抗病性及抗逆性等.试验表明:在崇左试验点综合性状表现良好的品种是桂糖 08-120、桂糖 08-1589,而桂柳 05-19、云蔗 11-3898、云瑞 10-187、福农 09-12206等品种易感黑穗病,且蔗产量偏低.

甘蔗品种比较试验是对特定区域甘蔗品种丰产性、稳产性和适应性的一种重要测试手段.通过对10个品种一年新植两年宿根进行比较试验,分析各参试品种的主要农艺性状、蔗茎产量、蔗糖分及含糖量、抗逆性,发现综合性状表现良好的品种是海蔗22号、桂糖06-2081、桂糖08-1180、福农09-2201等4个品种.研究结果可为崇左蔗区甘蔗新品种引进、示范和推广提供参考依据.

为探究葛68优9938高产栽培技术,在崇左市宁明县农科所试验田设置105 kg/hm2(N1)、150 kg/hm2(N2)、195 kg/hm2(N3)共3个不同施氮量和24万株/hm2(D1)、30万株/hm2(D2)、36万株/hm2(D3)共3个种植密度进行大田试验,对水稻品种葛68优9938穗长、产量构成因素和产量进行分析研究.结果表明,在同一施氮水平条件下,3个种植密度对穗长、产量构成因素和产量的影响较小,差异均不显著,但在N2水平时,可获得比较高的产量;在同一种植密度的条件下,穗长、产量构成因素和产量均随着施氮量的增加呈现先增加后减少的趋势,3个施氮水平对穗长、产量构成因素和产量影响均不显著,但在D2水平时,可以取得较高的产量.因此,在推广种植葛68优9938时,建议种植密度为30万株/hm2、施氮量为195 kg/hm2,能获得比较高的产量.

利用2b-RAD (type ⅡB endonucleases restriction-site associated DNA)技术对糯玉米品种‘沪玉糯3号’及其亲本进行简化基因组测序.通过与玉米‘B73’参考基因组序列进行比对,在3个糯玉米样品的共同测序标签内筛选出20 498个单核苷酸多态性(single nucleotide polymorphism,SNP)位点,并基于RADtyping分型策略对它们进行基因型分型.对其中20 333个位于玉米10条染色体上的SNP位点的基因型进行分析,开发出6个可用于‘沪玉糯3号’品种特异性鉴定的SNP分子标记.

为了提高糯玉米种质资源的利用效率,挖掘优异糯玉米种质资源、改良糯玉米品种,利用(Single nucleotide polymorphism,SNP)芯片技术对44份不同来源的糯玉米自交系和5份分别代表中国玉米5大类群的普通玉米自交系进行全基因组扫描.结果 表明,34257个SNP标记在49份玉米自交系中的多态性信息含量(polymorphism information content,PIC)为0.02～0.56,平均含量为0.32;最小等位基因频率(minor allele frequency,MAF)≥0.03.49份玉米自交系间的状态一致性(identity-by-state,IBS)变幅为0.59～0.99,平均为0.68.基于IBS利用Neighbor-joining(NJ)聚类分析方法,将49份自交系划分为5个类群,分别包含19份、9份、4份、9份和3份材料,其中系谱来源不清晰的糯玉米自交系被划分至不同类群,明确了它们的亲缘关系.

为构建糯玉米品种DNA指纹库,保护品种资源,利用Illumina公司研发的包含56 110个SNP标记的芯片,对50份糯玉米自交系进行基因分型.结果 表明:按照SNP标记选用标准,共得到42 406个SNP标记.这些标记的杂合率均值为0.04,SNP缺失率均值为0.01,最小等位基因频率(MAF)均值为0.4,多态性信息含量(PIC)均值为0.38,基因多样性指数均值为0.44.对上述获得的SNP标记设置不同数量位点进行筛选,确定25 000位点为核心标记位点,可用于构建糯玉米自交系DNA指纹库.在25 000位点时,对50份糯玉米自交系进行SNP聚类分析,共将其划分为四大类群,聚类结果与品种系谱来源一致.该研究可为糯玉米品种特异性和一致性的鉴定分析及品种保护工作提供理论指导.

以糯玉米申白甜糯1号、苏玉糯5号为试验材料,进行3种施氮水平对其生育期、穗部性状、产量及品质的影响试验.结果 表明,3种施氮水平下2个品种生育期都没有差异;667 m2施氮10、15 kg处理2个品种秃尖长差异不显著,但与不施氮处理相比,存在显著差异;2个品种2个施氮处理鲜穗产量显著高于不施氮处理;品尝品质总评分也比不施氮处理高.适当减少氮肥投入对糯玉米产量及品质没有影响,关键是找到氮肥对农艺性状、产量减少影响的临界值,从而避免过量氮素投入导致的资源浪费,实现稳产,提高氮肥的利用效率.

为了解糯玉米种质的遗传基础,利用29对SSR标记对87份糯玉米自交系进行遗传多样性分析,共检测出180个等位变异,平均每个位点6个等位变异,多态性信息含量变幅为0.308～0.915,平均为0.572.材料间遗传相似系数为0.49～0.93,平均为0.66.通过聚类分析UPGMA (unweighted pair-group method with arithmetic means)方法在遗传相似系数0.64处将87份糯玉米自交系划分为4个类群,分别包含9、66、10和2份材料.此外,利用Structure群体遗传结构分析也将87份糯玉米自交系分为4个类群,分别包含24、25、19和19份材料;进一步分析表明,供试群体中大部分糯玉米自交系的遗传变异较单一.本研究为糯玉米新品种选育和遗传进化分析提供了种质基础和理论依据.

以沪五彩花糯1号为试材,设6个采收期,研究采收期对子粒品质和糊化特性的影响.结果表明,采收期为授粉后20 d时,沪五彩花糯1号感官和蒸煮品质综合评分达最高,为85.6分.蛋白质和可溶性糖含量随采收期推迟而降低,而淀粉则相反.不同采收期下的峰值粘度、谷值黏度、终值黏度、崩解值和回复值变异系数要大于峰值时间和糊化温度的变异系数,说明除峰值时间和糊化温度之外,峰值黏度、谷值黏度、终值黏度、崩解值和回复值受采收期影响较大.与淀粉和可溶性糖相比,子粒中的蛋白质对糊化特性的影响较大.

‘沪五彩花糯1号’是以申W48为母本、申W93为父本杂交选育出的籽粒为五彩花色的优质糯玉米新品种.该品种在上海地区春播出苗至采收83 d,生育期与‘申糯2号’(CK)相仿,产量(去苞叶鲜穗净重)13 066.3 kg/hm2,比‘申糯2号’增产8.2％.该品种色泽鲜丽,鲜食糯性品质好,口感甜糯,综合评分85.6,抗病性好.

利用40对玉米SSR核心引物对2个供试品种进行DNA指纹鉴定,确定'沪玉糯3号'的真实性.通过在'沪玉糯3号'及其双亲间扩增,发现SSR标记umc2007y4、bnlg1940k7、bnlg2305k4、bnlg1702k1、umc1125y3、phi080k15能在样品与'沪玉糯3号'间扩增出清晰稳定的多态条带,因此,认为这6对SSR引物可用于'沪玉糯3号'品种真实性的快速鉴定.此外,筛选出6对共显性SSR核心引物(bnlg1940k7、bnlg2305k4、umc1536k9、bnlg249k2、bnlg2235y5和phi233376y1),可用于'沪玉糯3号'的纯度鉴定.SSR标记bnlg1940k7和bnlg2305k4作为首选,可同时对'沪玉糯3号'种子进行真实性和纯度鉴定.为加强'沪玉糯3号'的产权保护及种子质量监测提供了理论依据和技术支持.

A dwarf wheat mutant (NM9) with additional tillers and elongated spikes was obtained by treating NAU9918 seeds with ethyl methanesulfonate (EMS). The decreased plant height in NM9 was controlled by a novel dwarf gene Rht_NM9. The endogenous plant hormones play important roles in regulating plant height of common wheat. To understand the dwarfing mecha-nism of Rht_NM9 and the relationship between endogenous hormone contents and plant height, measured contents of endogenous gibberellic acid (GA), auxin (IAA), abscisic acid (ABA) and zeatin riboside (ZR) in internodes of NM9 and NAU9918 at different stages by enzyme-linked immunosorbent assays (ELISA). Our study indicated that contents of GA and ABA in NM9 were sig-nificantly higher than there in NAU9918, and ZR content in NM9 was significantly lower than that in NAU9918 at both booting and heading stages. Nevertheless, no difference of IAA content was observed between the mutant and the wild-type. In addition, the GA/ABA ratio in internodes of the mutant was significantly higher than that of the wild-type, however, the ratios of IAA/ABA, (IAA + GA)/ABA and ZR/ABA were significantly lower than there of the wild-type. All these results indicated that plant height in wheat was regulated by multiple hormones. Plant height would be inhibited with increasing content of endogenous ABA and de-creasing ratios of IAA/ABA and ZR/ABA in wheat.

The effects of 3 fertilization methods on the yield and related economic characters of 2 plant types of maize were studied in this paper,taking ‘ Huyunuo 5’ (compact type)and ‘ Huyunuo 2’ (fiat type)as materials.The results showed that the average yield of fertilization method A2 (11 531 kg/hm2) was the highest,the yield of ‘ Huyunuo 5 ’ was 12 997 kg/hm2,which was significantly higher than that of ‘ Huyunuo 2 ’ (9 168 kg/hm2).There were significant differences in ear barren tip,and no significant difference in ear length,ear diameter,row number,grain number per row,100-grain weight and seed rate between the 3 methods.There were very significant differences in ear length,ear diameter,row number,grain number per row,seed rate and ear barren tip,no significant difference in 100-grain weight between the 2 varieties.Therefore,the appropriate method of urea application was 315 kg/hm2 in seeding stage and 135 kg/hm2 in jointing stage respectively.The yield of compact type maize ‘ Huyunuo 5’ was significantly higher than that of fiat type maize ‘ Huyunuo 2’,which had good characters.

Stable purplish glutinous maize inbred line Shen-W93 was obtained from self-crossed progenies of Jingheinuo2 by characterized selection.Shen-W93 was characterized as high combining ability.In addition,both Shen-W93 and its hybrids,which were approved by provincial authorities,showing a high yield,good quality,high resistance,early coloring and color magnet after cooking.To date,these hybrid varieties have been applied to a total cultivated area of 10 000 hectares,which increased a benefit of 0.24 billion Yuan compared to general glutinous maize,for their good adaptabilities to plant in Southeast China and Southwest China.

'Wucaitiannuo 1'is a new sweet and waxy maize cultivar bred through crossing between'Shen w93'and'wh-1'.Its mature stage is 86 d from emergence to harvest spring in Shanghai,1.4 d later than 'Shennuo 2'(CK).Its net weight is 12 688.6 kg/hm2,increased by 9.6％ than'Shennuo 2'.The quality comprehensive score is 89.2.The variety of high quality is good sweet and taste waxy corn.

对50份不同来源糯玉米品种的农艺性状和产量进行了鉴定,并利用40个SSR标记对其进行遗传多样性分析.结果表明:50份糯玉米秃尖长、穗位高、毛重和净重变异较大.40个SSR标记在50份糯玉米品种上共检测到190个等位基因变异,等位基因变异范围为2-9,平均每个位点检测到4.75个等位基因.每对SSR标记的多态性信息量(PIC)变化范围在0.430—0.844,平均为0.675.利用UPGMA聚类分析方法进行聚类,共划分为3个主要类群,聚类结果与品种的来源基本一致.50份糯玉米品种遗传多样性丰富,为组配糯玉米杂交新品种和遗传改良提供基础.