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71.
J Crossa P Pérez J Hickey J Burgue?o L Ornella J Cerón-Rojas X Zhang S Dreisigacker R Babu Y Li D Bonnett K Mathews 《Heredity》2014,112(1):48-60
Genomic selection (GS) has been implemented in animal and plant species, and is regarded as a useful tool for accelerating genetic gains. Varying levels of genomic prediction accuracy have been obtained in plants, depending on the prediction problem assessed and on several other factors, such as trait heritability, the relationship between the individuals to be predicted and those used to train the models for prediction, number of markers, sample size and genotype × environment interaction (GE). The main objective of this article is to describe the results of genomic prediction in International Maize and Wheat Improvement Center''s (CIMMYT''s) maize and wheat breeding programs, from the initial assessment of the predictive ability of different models using pedigree and marker information to the present, when methods for implementing GS in practical global maize and wheat breeding programs are being studied and investigated. Results show that pedigree (population structure) accounts for a sizeable proportion of the prediction accuracy when a global population is the prediction problem to be assessed. However, when the prediction uses unrelated populations to train the prediction equations, prediction accuracy becomes negligible. When genomic prediction includes modeling GE, an increase in prediction accuracy can be achieved by borrowing information from correlated environments. Several questions on how to incorporate GS into CIMMYT''s maize and wheat programs remain unanswered and subject to further investigation, for example, prediction within and between related bi-parental crosses. Further research on the quantification of breeding value components for GS in plant breeding populations is required. 相似文献
72.
73.
Sen Wang Fei Zheng Meijing Zhang Jun Tu Yanping Chen Jianhua Yuan Qingchang Meng 《Phyton》2020,89(4):861-871
Endosperm mutants are critical to the studies on both starch synthesis
and metabolism and genetic improvement of starch quality in maize. In the present study, a novel maize endosperm mutant A0178 of natural variation was used
as the experimental material and identified and then characterized. Through phenotypic identification, genetic analysis, main ingredients measurement and
embryo rescue, development of genetic mapping population from A0178, the
endosperm mutant gene was located. The results showed that the mutant exhibited
extremely low germination ability as attributed to the inhibited embryo development, and amounts of sugars were accumulated in the mutant seeds and more
sugars content was detected at 23 days after pollination (DAP) in A0178 than
B73. Employing genetic linkage analysis, the mutant trait was mapped in the
bin 5.04 on chromosome 5. Sequence analysis showed that two sites of base transversion and insertion presented in the protein coding region and non-coding
region of the mutant brittle-1 (bt1), the adenylate translocator encoding gene
involved in the starch synthesis. The single base insertion in the coding region
cause frameshift mutation, early termination and lose of function of Brittle-1
(BT1). All results suggested that bt1 is a novel allelic gene and the causal gene
of this endosperm mutant, providing insights on the mechanism of endosperm formation in maize. 相似文献
74.
由小麦×玉米获得的普通小麦加倍单倍体后代的RFLP变异 总被引:3,自引:0,他引:3
用小麦(Triticum aestivumL.)的rDNA克隆pTa71和与小麦基因组有部分同源性的玉米(ZeamaysL.)DNA克隆作探针,对由小麦x玉米获得的普通小麦加倍单倍体(DH)后代群体进行RFLP分析。结果发现,不但用pTa71在这些DH后代中检测到rDNA所发生的明显的减少和扩增及非转录间隔区的限制性片段长度的变化,而且用与小麦基因组部分同源的玉米克隆MR13和MR50在一些DH后代中检测到缺失变异,特别是用MR13在普通小麦DH系的18号株的基因组中检测到大幅度的限制性片段长度的变化,即原来的4.3kb的强信号带消失,取而代之的是40.0kb、2.5kb和2.0kb三条杂交带。这可能与小麦基因组DNA较大的重排事件有关,也可能是由外源的玉米DNA插入造成的。 相似文献
75.
为研究玉米(Zeamays L.)19kD醇溶贮藏蛋白(zein)基因启动子种子特异性表达的控制区段,将全长694bp的启动子进行5’端缺失,共得到6个缺失突变体,长度分别为488bp、378bp、302bp、152bp、124bp和85bp。将6个片段分别与报告基因gus连接构建成表达载体pDGB系列,经土壤农杆菌(Agrobacterium)介导转化,引入烟草。GUS活性检测证明,488bp启动子片段能促使gus基因在种子中特异表达。378bp、302bp、152bp和124bp片段启动子引导的gus基因在烟草根、叶柄、种子中均可表达。 相似文献
76.
A promoter fusion (Sh35) combining upstream regulatory regions from the maize Sh1 promoter with a truncated 35S promoter, Δ9035 (–90 to +8) has been compared with the original Sh1 promoter for its capacity to promote expression of the β-glucuronidase (GUS) gene in stably transformed tomato plants. For both promoters, very faint GUS expression was detected
in the vegetative tissues, and no expression was detected in the fruit pericarp tissues. However, in the seed, Sh1 promoted low GUS expression but Sh35 directed 25-fold higher GUS expression. For both constructs, the profile of GUS expression
was similar to that of endogenous sucrose synthase activity, but maximal GUS activity was reached 15 days after the peak of
sucrose synthase activity.
Received: 20 October 1998 / Revision received: 1 December 1998 / Accepted: 14 December 1998 相似文献
77.
玉米中哺乳动物细胞凋亡相关基因rb同源序列的检出及其荧光原位杂交 总被引:1,自引:0,他引:1
杨征 《Acta Botanica Sinica》1999,41(12):1339-1341
细胞凋亡 (apoptosis)是当今发育生物学研究的热点之一。成视网膜细胞瘤 (retinoblastoma ,rb)基因是动物中第一个被克隆的肿瘤抑制基因 ,当细胞中缺失rb产物时 ,导致细胞凋亡。本研究采用South ern杂交技术 ,进一步证明玉米和水稻基因组中具有rb基因的同源序列 ,并利用染色体原位杂交技术 ,首次确定了这一序列在玉米染色体上的位置。1 材料和方法1 1 实验材料供试玉米 (ZeamaysL .)品种为“黄早四”和“大红袍” ,供试水稻 (OryzasativaL .)品种为“鄂早 6号”。人rb基因的… 相似文献
78.
陈汝民 《热带亚热带植物学报》1999,7(1):70-74
已有研究证实,6-甲氧基-2-并噁唑啉酮(6-methoxy-2-benzoxazolinone,MBOA)是引起玉米胚芽鞘向光性运动的主要物质。本文采用生物测定和HPLC分析等方法,对MBOA的生理作用特点做进一步的探讨,结果表明:1.光刺激下收集的胚芽鞘分泌物主要成份是MBOA,该物质明显抑制鸡冠花和水芹下胚轴的伸长。2.将MBOA与IAA混合处理胚芽鞘,产生相互拮抗的效果。3.单侧放置含MBOA琼脂块能引起去顶胚芽鞘弯曲生长。4.伤害胁迫使胚芽鞘MBOA含量增加。因此,MBOA不仅是引起植物向光性运动的物质,也是与抗伤害胁迫有关的天然抑制物质,其生理功能之一是与生长素的作用相互拮抗,并抑制植物生长。 相似文献
79.
从不同人工老化处理中筛选出3组分别代表不同活力的玉米种子。萌发期间,中、低活力种子胚蛋白的降解比高活力对照种子慢,萌发前期胚蛋白合成能力也较低。吸胀24h,不同活力胚的蛋白合成能力差异显著,可以作为衡量种子活力的指标。 相似文献
80.
RFLP mapping of quantitative trait loci controlling abscisic acid concentration in leaves of drought-stressed maize (Zea mays L.) 总被引:7,自引:0,他引:7
R. Tuberosa M. C. Sanguineti P. Landi S. Salvi E. Casarini S. Conti 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):744-755
Abscisic acid (ABA) concentration in leaves of drought-stressed plants is a quantitatively inherited trait. In order to identify
quantitative trait loci (QTLs) controlling leaf ABA concentration (L-ABA) in maize, leaf samples were collected from 80 F3:4 families of the cross Os420 (high L-ABA)×IABO78 (low L-ABA) tested under drought conditions in field trials conducted over
2 years. In each year, leaf samples were collected at stem elongation and near anthesis. The genetic map obtained with 106
restriction fragment length polymorphism (RFLP) loci covered 1370 cM, which represented approximately 85% of the UMC maize
map. Sixteen different QTLs with a LOD>2.0 were revealed in at least one sampling. Across samplings, only four QTLs significantly
influenced L-ABA, accounting for 66% of the phenotypic variation and 76% of the genetic variation among families. At these
QTLs, the alleles which increased L-ABA were contributed by Os420. The two most important QTLs were mapped on chromosome 2
near csu133 and csu109a. The effects associated with the QTL near csu133 were more pronounced near anthesis. The support intervals of the four primary QTLs for L-ABA did not overlap the presumed
map position of mutants impaired in ABA biosynthesis.
Received: 27 January 1998 / Accepted: 22 April 1998 相似文献