Genomic prediction of yield performance among single-cross maize hybrids using a partial diallel cross design

Genomic prediction(GP)in plant breeding has the potential to predict and identify the best-performing hybrids based on the genotypes of their parental lines.In a GP experiment,34 elite inbred lines were selected to make 285 single-cross hybrids in a partial-diallel cross design.These lines represented a mini-core collection of Chinese maize germplasm and comprised 18 inbred lines from the Stiff Stalk heterotic group and 16 inbred lines from the Non-Stiff Stalk heterotic group.The parents were genotyped by sequencing and the 285 hybrids were phenotyped for nine yield and yield-related traits at two locations in the summer sowing area(SUS)and three locations in the spring sowing area(SPS)in the main maizeproducing regions of China.Multiple GP models were employed to assess the accuracy of trait prediction in the hybrids.By ten-fold cross-validation,the prediction accuracies of yield performance of the hybrids estimated by the genomic best linear unbiased prediction(GBLUP)model in SUS and SPS were 0.51 and 0.46,respectively.The prediction accuracies of the remaining yield-related traits estimated with GBLUP ranged from 0.49 to 0.86 and from 0.53 to 0.89 in SUS and SPS,respectively.When additive,dominance,epistasis effects,genotype-by-environment interaction,and multi-trait effects were incorporated into the prediction model,the prediction accuracy of hybrid yield performance was improved.The ratio of training to testing population and size of training population optimal for yield prediction were determined.Multiple prediction models can improve prediction accuracy in hybrid breeding.

Isolation and Identification of Submergence-induced Genes in Maize (Zea mays) Seedlings by Suppression Subtractive Hybridization

To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedling roots treated with submergence (ST) was used as tester and what from untreated roots (UT) as driver. Products of the secondary PCR from the forward subtraction were cloned into T/A vector and transferred into Escherichia coli strain JM10B by electroporation. Four hundred and eight randomly chosen transformants carrying cDNA fragments were screened with PCR-Select Deferential Screening Kit. One hundred and eighty-four cDNA clones were identified as, submergence specifically induced or highly expressed. After sequencing and removing redundant cDNAs, we got 95 submergence-induced cDNA clones. Of the 95 cDNA clones, 68 contain the regions with 60%-90% identity to their homolog in GenBank, 21 are expected to be novel genes, only 6 correspond to the published maize sequences.

Research and Breeding Application Progress of the Technique of Producing Double Haploid of Wheat by Wide Hybridization between Wheat and Maize

The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is the most efficient and has great potential of application in breeding of wheat. This article reviewed princi- ple and production process of the technique, research situation of the three key in- dicators of the technology（embryo rate, seedling rate and success rate of doubling）in recent years, and application of the technology in breeding, genetics, germplasm improvement of wheat. At last, both the achievements and the direction of further improvement and development of the technology in our program were discussed.

黄土旱塬Hybrid-Maize模型适应性及春玉米生产潜力估算

通过对Hybrid-Maize玉米高产模型进行田间验证,应用该模型对黄土旱塬春玉米生产潜力进行初步估算。结果表明,Hybrid-Maize模型在黄土旱塬表现出较好模拟效果,总生物量、秸秆生物量和籽粒产量模拟值与实测值间具有极显著线性相关性,其决定系数分别为0.9469、0.8164和0.9650,回归系数分别为1.0198、0.9787和1.1844,接近于1。黄土旱塬区多年光温生产潜力和气候生产潜力因品种不同有所差别,对多年平均光温籽粒和总生物量生产潜力,紧凑型玉米品种分别为13.25和22.45t/hm2,平展型玉米品种分别为12.32和20.62t/hm2,年际变化小;对多年平均气候籽粒和总生物量生产潜力,紧凑型玉米品种分别为11.97和19.94t/hm2,平展型玉米品种分别为11.37和18.63t/hm2,年际波动大。在黄土旱塬区,玉米产量潜力挖掘的主要途径应集中在提高密度和水分限制条件下,Hybrid-Maize玉米模型在指导玉米高产栽培上具有较好应用。

基于Hybrid-maize模型的吉林省不同生态区玉米产量潜力研究

为挖掘玉米产量潜力,进一步提升玉米综合生产能力,利用在东北地区已验证的Hybrid-maize模型及多年气象数据对吉林省不同生态类型区[东部湿润生态区(桦甸)、中部半湿润生态区(公主岭)、西部半干旱生态区(乾安)]不同品种、播期和密度及其相互组合下的玉米产量潜力进行模拟,并对影响玉米高产稳产的因素进行定量分析,同时考虑产量潜力变异情况及品种本身的生产特性,构建了吉林省不同生态区玉米高产体系。研究结果表明:1)改变播期是一项重要的增产措施,不同生态区的表现不同,湿润区应选择早播,播种日期在4月20日左右较适宜,而半湿润和半干旱地区应尽量晚播,适宜播期应在5月中旬左右。2)不同生态区对密度的容纳能力表现为湿润区(桦甸)>半湿润区(公主岭)>半干旱区(乾安),3个地区的适宜密度分别为90 000株·hm^(-2)、80 000株·hm^(-2)和75 000株·hm^(-2)左右。3)选用生育期更长的品种表现出了较高的增产潜力,生产上应根据不同区域生态条件,尽量选择晚熟品种,在当前播期条件下半湿润和半干旱地区品种生育期内需要的有效生长积温(GDD)可增至1 600℃以上。4)与当前生产技术相比,将播期、密度、品种三者优化组合,高产体系长期平均产量潜力可增产14.39%~29.23%。本研究可为吉林省玉米高产措施的正确应用提供理论依据,为玉米产量大面积提升提供技术参考。

基于密度联网试验和Hybrid-Maize模型的内蒙古玉米产量差和生产潜力评估

采用科学方法对内蒙古玉米产量差与生产潜力进行定量化研究,对合理规划内蒙古玉米增产途径及产业发展具有重要意义。本研究采用品种×密度联网试验和Hybrid-Maize模型模拟相结合的方法,利用2006年以来内蒙古各生态区历年高产攻关田的最高实测产量和各区域农户平均产量,对内蒙古全区和6大生态类型区的玉米产量差和生产潜力进行了系统分析。结果表明,各生态区的模拟产量、高产纪录、试验产量、农户产量皆表现为从东到西逐步提高。内蒙古玉米模拟产量潜力为14.9 t×hm^(-2),高产纪录产量为14.4 t×hm^(-2),试验产量为11.1 t×hm^(-2),农户产量分别实现了模拟产量潜力的49%、高产纪录产量的51%和试验产量的66%。基于模型模拟的产量差(YGM)、基于高产纪录的产量差(YGR)和基于试验产量的产量差(YGE)分别为7.5 t×hm^(-2)、7.0 t×hm^(-2)和3.8 t×hm^(-2)。基于YGE的短期生产潜力达3 525.2万t,是当前总产水平的1.6倍,短期增产潜力为1 191.9万t。其中,内蒙古东部的呼伦贝尔、兴安盟、通辽、赤峰4盟市对全区的增产贡献率将达61%,西部的呼和浩特市、巴彦淖尔市为16%。造成较大YGE主要原因是栽培管理措施不当,缩小YGE需要针对限制各生态区玉米增产的实际问题,通过栽培技术综合改良、技术简化和技术入户来逐步实现。

Isolating Soil Drought-Induced Genes from Maize Seedling Leaves Through Suppression Subtractive Hybridization

In this study, a forward cDNA library was constructed by suppression subtractive hybridization using seedling leaves of CN165, a drought-tolerant maize inbred line. In the suppression subtractive hybridization （SSH） library, 672 positive clones were picked up randomly. After polymerase chain reaction （PCR） of each clone, all the single clones were sequenced. Totally 598 available sequences were obtained. After cluster analysis of the EST sequences, 80 uniESTs were obtained, among which 57 uniESTs were contigs and 23 uniESTs were singlets. The results of BLASTN showed that all the uniESTs had homologous sequences in the nr database. The BLASTX results indicated that 68 uniESTs had significant protein homology, 8 uniESTs with homology of unknown proteins and putative proteins, and 4 uniESTs without protein homology. Those drought stress-induced genes were involved in many metabolism pathways to regulate plant growth and development under drought stress.

Factors influencing hybrid maize farmers' risk attitudes and their perceptions in Punjab Province,Pakistan

Hybrid maize farmers have to face diverse kinds of climate, biological, price and financial risks. Farmers＇ risk perceptions and risk attitudes are essential elements influencing farm operations and management decisions. However, this important issue has been overlooked in the contemporary studies and therefore there is a dearth of literature on this important issue. The present research is therefore, an attempt to fill this gap. This study aims to quantify hybrid maize farmers＇ perceptions of disastrous risks, their attitudes towards risk and to explore the impacts of various farm and farm household factors on farmers＇ risk attitudes and risk perceptions. The present study is conducted in four hybrid maize growing districts of Punjab Province, Pakistan, using cross-sectional data of 400 hybrid maize farmers. Risk matrix and equally likely certainty equivalent （ELCE） method are used to rank farmers＇ perceptions of four catastrophic risk sources including climate, biological, price and financial risks and to investigate farmers＇ risk aversion attitudes, respectively. Furthermore, probit regression is used to analyze the determinants affecting farmers＇ risk attitudes and risk perceptions. The results of the study showed that majority of farmers are risk averse in nature and perceive price, biological and climate to be potential sources of risks to their farm enterprise. In addition, analysis divulges that distance from farm to main market, off-farm income, location dummies for Sahiwal and Okara, age, maize farming experience, access to extension agent, significantly （either negatively or positively） influence farmers＇ risk attitudes and risk perceptions. The study delivers valuable insights for farmers, agricultural insurance sector, extension services researchers and agricultural policy makers about the local understanding of risks to hybrid maize crop in developing countries, like Pakistan, and have implications for research on farmers＇ adaptation to exposed risks.

The Optimal Time for Harvesting the Seeds of Gui 39722, the Female Parent of a Maize Hybrid Guidan 0810

To determine the optimal time for harvesting the seeds of Gui 39722, which is the female parent of a newly-developed maize hybrid Guidan 0810, the cobs of Gui 39722 were harvested 31 （the first stage）, 34 （the second stage）, 37 （the third stage）, 40 （the fourth stage）, 43 （the fifth stage） and 46 （the sixth stage） d after pollination and oven dried at 38 ~C to constant weight. Then, the 1 000-ker- nel weight, germination rate and the agronomic traits of three-leaf seedlings were measured and compared. The results showed that the seeds of Gui 39722 harvest- ed 43 d after pollination （the fifth stage） had the greatest germination rate, seedling height, vigor index, root dry weight, shoot dry weight and germination potential, and high 1 000-kernel weight （very close to the highest level）, root length, number of roots per seedling and root-shoot ratio. Therefore, 43 d after pollination was the op- timal time for harvesting the seeds of Gui 39722, when the effective accumulated temperature after pollination reached 780.7 ℃ and the ear leaf dried. The seeds harvested at this stage had the highest yield and the best quality. Field sampling revealed that 89.00% to 95.00% （with an average of 91.15%） of the seedlings of six stages of seeds grew well.

Differential Expression of microRNAs in Maize Inbred and Hybrid Lines during Salt and Drought Stress

Here, we analyzed whether the microRNA (miRNA) expression levels differ between maize inbred lines B73 and Mo17 and their reciprocal hybrids under salt and drought stress. We found that miR156, miR164, miR166, miR168, miR171 and miR319 are differentially expressed under abiotic stress. Interestingly, Mo17 × B73 showed the strongest change in miRNA expression in response to salt or drought stress, and was also the most resilient line when under abiotic stress in terms of water loss. In summary, our findings open the possibility that differential miRNA expression levels might be involved in heightened stress tolerance in maize hybrids.

Influence of Zinc Nutrition on Growth and Yield Behaviour of Maize (<i>Zea mays</i>L.) Hybrids

A field experiment was conducted during spring 2011 at Agronomic Research Area, University of Agriculture, Faisalabad, Pakistan to evaluate the comparative efficacy of Zn uptake and grain yield in three maize hybrids namely Pioneer-32F 10, Monsanto-6525 and Hycorn-8288 through the application of Zn in the form of ZnSO4. The ZnSO4 treatments comprised;soil application at the time of sowing @ 12 kg&middotha-1 (Zn1), foliar application at vegetative stage (9 leaf stage) @ 1% ZnSO4 solution (Zn2) and foliar application at reproductive stage (anthesis) @ 1% ZnSO4 solution (Zn3) and one treatment was kept as a control, where zinc was not applied (Zn0). The experimental results showed substantial difference in all physiological and yield parameters except plant height and stem diameter. Statistically maximum grain yield (8.76 t&middotha-1) was obtained with foliar spray of ZnSO4 at 9 leaf stage (Zn2) in case of Monsanto-6525. As regard to quality parameters, Pioneer-32F 10 and Hycorn-8288 accumulated more zinc contents in grains but Monsanto-6525 attained more zinc concentration in straw. Foliar spray of ZnSO4 at 9 leaf stage produced 19.42% more zinc contents in grains as compared to other ZnSO4 treatments. Foliar spray of ZnSO4 at 9 leaf stage in Monsanto-6525 hybrid produced higher grain yield.

Breeding for Parents of Hybrid Rice with Maize pepc Gene

The results of the investigation on transgenic rice with maize C4-specific phosphoenolpyruvate carboxylase (pepc) gene showed that the transgenic rice plants with the maize pepc gene expressed at high level and the maize PEPC expression was inherited in the progenies in a Mendelian manner. The transgenic plants had PEPC activity of more than 10-fold higher than untransformed plants. As compared with untransformed plants, the panicle per plant, spikelet per panicle, 1000-grain weight and grain-weight per plant for transgenic plants increased by 14.9 % , 5.7%, 1.3 % and 13.9 %, respectively. By crossing the maize pepc gene was incorporated into the parents of hybrid rice, which were the photo-sensitive genie male sterile (PGMS) lines of two-line hybrid rice such as Peiai64s, 7001s, 2302s, 2304s and 2306s-1, and the BT type of cytoplas-mic male sterile (CMS) line of three-line hybrid rice such as Shuangjiu A, and restorer lines 5129, Wanjing97 in the spring of 1998. The following progresses were made: (1) The inheritance of the high-level expression of the maize PEPC was stable in different genetic background of rice; (2) PEPC activity of hybrid was the mean of the two parents. Its saturated photosynthetic rate (Pn) rose to 50 % higher than that of the receptor parent. These results demonstrated that it is possible to increase the vigor of the rice plant by transgenic approach with maize pepc gene; (3) The activity of PEPC in leaf could be considered as the major physiological index because the correlation coefficient between PEPC activity and Pn was 0.6470* * ; (4) We have developed three rice lines with maize pepc gene; (5) The selection method of high photosynthetic efficiency rice has been established, which includes soaking seeds into solution of hygromycin phosphotransferase to germinate, tracing the pepc gene by PCR analysis, evaluating the performance of the rice plants in the field and examining PEPC activities and Pn of rice plants with maize pepc gene.

Development and application of marker-assisted reverse breeding using hybrid maize germplasm

Humankind has been through different periods of agricultural improvement aiming at enhancing our food supply and the performance of food crops. In recent years, whole genome sequencing and deep understanding of genetic and epigenetic mechanisms have facilitated new plant breeding approaches to meet the challenge of growing population, dwindling resources, and changing climate. Here we proposed a simple and fast molecular breeding method, marker-assisted reverse breeding（MARB）, which will revert any maize hybrid into inbred lines with any level of required similarity to its original parent lines. Since all the pericarp DNA of a hybrid is from the maternal parent, whereas one half of the embryo DNA is from the maternal parent and the other half from the paternal parent, so we firstly extract DNA from seed embryo and pericarp of a selected elite hybrid separately and then we derived the genotypes of the two parents with high-density single nucleotide polymorphism（SNP） chips. The following marker-assisted selection was performed based on an Illumina low-density SNP chip designed with 192 SNPs polymorphic between the two parental genotypes, which were uniformly distributed on 10 maize chromosomes. This method has the advantages of fast speed, fixed heterotic mode, and quick recovery of beneficial parental genotypes compared to traditional pedigree breeding using elite hybrids. Meanwhile, MARB has the advantage of not requiring sophisticated transformation and double haploid（DH） technologies over RNA interference（RNAi）-mediated reverse breeding. In addition, MARB can also be used with feed corn harvested from big farms, which is often similar to F_2 populations, and the relevant transgenes in the population can be eliminated by marker-assisted selection. As a result, the whole global commercial maize hybrids can be utilized as germplasm for breeding with MARB technology. Starting with an F_2 population derived from an elite hybrid, our experiment indicates that with three cycles of marker-assisted selection, selected lines could recover over 80% of the parental genotypes and associated beneficial genes in a fixed heterotic mode. The success application of MARB in maize suggests that this technology is applicable to any hybrid crop to breed new inbreds with improved hybrid performance but the same heterotic mode. As chip technology becomes cheap, it would be expected that polymorphism screening and following marker-assisted selection could be done with one all-purpose high density chip. Several issues associated with MARB were discussed, including its rationale, efficiency and advantages, along with food/feed and environmental safety issues and applications of MARB in variety protection and marker-assisted plant breeding.

Chromosome G-banding in SituHybridization of RFLP Marker umc58 Linked with the Gene hm1 Dictating Helminthosporium carbonum Susceptibility1 in Maize

The technique of simultaneous G banding and in situ hybridization has been developed in plants for the first time.Using this technique.RFLP marker umc58 closely linked with the hm1 gene dictating Helminthosporium carbonum susceptibility1 was localized onto 1L3(chromosome 1,long arm,the third band from the centromere to the end of the arm),5L5 and 9L5.Theresults demonstrated that umc58 was a tripli cated sequence.It was deduced that umc58 probably was in a duplicated region that includes a part of Helminthosporium carbonum susceptibility genes(hm1 and hm2),as the hybridization sites of umc58 in chro mosomes 1 and 9 were those at which the genes localize.The techniques of simultaneous G banding and ISH in plants are discussed.

Omics Technologies Reveal Abundant Natural Variation in Metabolites and Transcripts among Conventional Maize Hybrids

In this report we have evaluated metabolite and RNA profiling technologies to begin to understand the natural variation in these biomolecules found in commercial-quality, conventional (non-GM) maize hybrids. Our analyses focus on mature grain, the article of commerce that is most typically subjected to the rigorous studies involved in the comparative safety assessment of GM products. We have used a population of conventionally-bred maize hybrids that derive from closely related inbred parents grown under standard field conditions across geographically similar locations. This study highlights the large amount of natural variation in metabolites and transcripts across conventional maize germplasm grown under normal field conditions, and underscores the critical need for further extensive studies before these technologies can be seriously considered for utility in the comparative safety assessment of GM crops.

Conversion of a normal maize hybrid into a waxy version using in vivo CRISPR/Cas9 targeted mutation activity

Waxy maize is a specialty maize that produces mainly amylopectin starch with special food or industrial values. The objective of this study was to overcome the limitations of wx mutant allele acquisition and breeding efficiency by conversion of parental lines from normal to waxy maize. The intended mutation activity was achieved by in vivo CRISPR/Cas9 machinery involving desired-target mutation of the Wx locus in the ZC01 background,abbreviated as ZC01-DTM^(wx). Triple selection was applied to segregants to obtain high genome background recovery with transgene-free wx mutations. The targeted mutation was identified, yielding six types of mutations among progeny crossed with ZC01-DTM^(wx).The amylopectin contents of the endosperm starch in mutant lines and hybrids averaged94.9%, while those of the wild-type controls were significantly(P < 0.01) lower, with an average of 76.9%. Double selection in transgene-free lines was applied using the Bar strip test and Cas9 PCR screening. The genome background recovery ratios of the lines were determined using genome-wide SNP data. That of lines used as male parents was as high as98.19% and that of lines used as female parents was as high as 86.78%. Conversion hybrids and both parental lines showed agronomic performance similar to that of their wild-type counterparts. This study provides a practical example of the efficient extension of CRISPR/Cas9 targeted mutation to industrial hybrids for transformation of a recalcitrant species.

Drying Temperature Effect on Kernel Damage and Viability of Maize Dried in a Solar Biomass Hybrid Dryer

Though several maize varieties have been developed and introduced over the years in Ghana, farmers still face challenges of access to quality seed maize. Among the major constraint is lack of proper drying systems to guarantee quality of seed produced. As in most parts of Africa, drying of maize in the open, on bare ground along shoulders of roads is still a common practice in Ghana. In this study, a 5-tonne capacity hybrid solar biomass dryer was developed for drying maize for seed and food/feed in Ghana. Effect of air temperature in the dryer on the physiological quality and germination of maize kernels was investigated. Maize grains were dried in the open sun simulating farmers practice and using the dryer at 4 varying levels (L1, L2, L3 and L4) with corresponding heights (0.6 m, 1.2 m, 1.8 m and 2.4 m, respectively) from the ground. Harvested maize at 22.8% moisture content was dried at the varying levels until reaching the final desired moisture content of 12.8% ± 0.2% (wb). Results showed that, air temperatures in the dryer increased in accordance with height with lowest mean temperature of 44.4&degC ± 4.6&degC recorded at L1 and mean maximum of 52.8&degC ± 5.4&degC at L4. Drying temperatures recorded at L1 - L3 and ambient had no significant effect (p < 0.05) on kernel damage and viability. Drying conditions at L1-L3 were considered optimum (<50&degC) for kernel drying compared to the topmost tray, L4. Kernel stress crack index (multiple and checked) was therefore reduced on average by 14% while kernel germination increased by 33%. This satisfies the dryer’s potential to be used for commercial drying of maize grains for seed production for smallholder farmers in Ghana.

Patience with density and reasonable use of different plant types in maize hybrids

The appropriate density of the hybrids with different plant morphotypes and grainyield of main maize hybrids in Henan province under different conditions and in different placeshave been studied for many years.The results indicalte that all the light intensity in middle andlow part of the plant,the single leaf weight(SLW) and the photosynthetic intensity decrease re-markably with the increase of plant density and leaf area index(LAI),and that all the charactersof the sirgle plant yield becorne inferior with different magnitudes.But the seriousness is slighterfor compact type hybrids than that for spread ones.Under high yield condition,the desirabledensity is 4250 to 5000 plants per mu(666. 67m^2)for compact maize hybrids and 3300 to 3500plants for spread ones.The yield differences between the two kinds of hybrid vary with the yieldlevels.

Physical Location of Terminal Markers Belonging to Five Linkage Groups in Maize RFLP Map Using in Situ Hybridization

Ten terminal or subterminal RFLP markers belonging to linkage groups 1, 3, 5, 6, and 10 in maize RFLP map were physically located onto maize mitotic chromosomes with in situ hybridization. All biotinylated probes from 600 to 2 250 bp were detected by DAB staining. The markers belonging to linkage groups 1, 3, 5, 6, and 10 correspondingly located at the chromosomes 1, 3, 5, 6, and 10. All of the tested markers except bnl6.25 and umc44 were duplicated sequences. Each of them was also labeled on another chromosome besides on the chromosome corresponding to its linkage group. The marker bnl3.04 was triplicated sequences and the signals were detected on three nonhomologous chromosomes. In the tested ten markers, there were only four located at the ends of corresponding chromosomes. Others were located at sites midway along the chromosome arms or near the centromeres. The region covered by two terminal or subterminal markers in each of linkage groups 1, 3, 5, and 6 occupied 80.02%, 38.25%, 82.30% and 51.16% of the region of both short and long arms in chromosomes 1, 3, 5,and 6 respectively. Only two terminal markers of linkage group 10 covered the whole chromosome 10. In some linkage groups, two terminal or subterminal markers covered a short genetic distance but were physically distant, while two covering a longer genetic distance were physically closer.

Genetic Variability and Path Analysis Studies in Hybrid Maize (<i>Zea mays</i>L.)

The present study was carried out to access correlation coefficient, path analysis and genetic variability among twenty one locally developed maize hybrids for ten characters. Positive and significant genotypic, phenotypic correlation coefficient were recorded for yield with anthesis silking interval (rg = 1.00**, rp = 0.96**), cob diameter (rg = 0.99** and rp = 0.95**) and ear height (rg = 0.98** and rp = 0.94**). But days to 50% tasseling had moderate but significant positive correlation at both phenotypic and genotypic level. High genotypic coefficient of variation (GCV) was obtained from thousand seed weight, days to 50% silking, cob diameter and anthesis silking interval. The highest phenotypic coefficient of variation (PCV) was observed in thousand seed weight followed by days to 50% silking and cob diameter. The highest heritability (Hb) was observed for cob diameter (95.25) followed by days to 50% silking (94.15), days to maturity (93.85) and ear height (93.06). The characters with high GCV and higher values of heritability indicated high potential for selection. Anthesis silking interval (0.79) had the highest positive direct effect on yield followed by cob diameter (0.31), cob length (0.31) and plant height (0.04) indicating the effectiveness of direct selection. While some other characters such as days to 50% tasseling (-0.12), days to 50% silking (-1.78), ear height (-1.16), days to maturity (-0.64) exhibited indirect negative effect on yield indicating the effectiveness of indirect selection.