• Title/Summary/Keyword: Maize

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Inhibitors Targeting ABA Biosynthesis and Catabolism Can Be Used to Accurately Discriminate between Haploid and Diploid Maize Kernels during Germination

  • Kwak, Jun Soo;Kim, Sung-Il;Song, Jong Tae;Ryu, Si Wan;Seo, Hak Soo
    • Plant Breeding and Biotechnology
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    • v.5 no.3
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    • pp.204-212
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    • 2017
  • There is a growing preference for using doubled haploids (DHs) in maize breeding programs because they reduce the time required to generate and evaluate new lines to 2 years or less. However, there is an urgent need for efficient techniques that accurately discriminate between haploid and diploid maize kernels. Here, we investigate the effects of several hormones and chemicals on the germination of haploid and diploid maize kernels, including auxin, cytokinin, ethylene, abscisic acid (ABA) biosynthesis inhibitor (fluridone), ABA catabolism inhibitor (diniconazole), methyl jasmonate (MeJA), and NaCl. Ethylene effectively stimulated the germination of both haploid and diploid maize kernels. The ABA biosynthesis inhibitor fluridone, the ABA catabolism inhibitor diniconazole, and MeJA selectively stimulated the germination of haploid maize kernels. By contrast, gibberellin, 1-naphthaleneacetic acid (NAA), kinetin, and NaCl inhibited the germination of both haploid and diploid maize kernels. These results indicate that the germination of haploid maize kernels is selectively stimulated by fluridone and diniconazole, and suggest that ABA-mediated germination of haploid maize kernels differs from that of diploid maize kernels and other plant seeds.

Effect of continuous maize cultivation on soil condition and yield in Northern Laos

  • Fujisao, Kazuhiko;Khanthavong, Phanthasin;Oudthachit, Saythong;Matsumoto, Naruo;Homma, Koki;Asai, Hidetoshi;Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • pp.346-346
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    • 2017
  • In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

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Influence of Maize and Cowpea Intercropping on Fodder Production and Characteristics of Silage

  • Azim, A.;Khan, A.G.;Nadeem, M.A.;Muhammad, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.6
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    • pp.781-784
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    • 2000
  • A study was conducted to examine the influence of maize (Zea mays) and cowpea (Vigna unguniculata) intercropping on fodder biomass production and silage characteristics. Maize fodder was cultivated alone and intercropped with cowpea at seed ratio of 85:15 and 70:30. Fodder was harvested at heading stage (at about 35% dry matter). The data indicated significant increase in biomass and crude protein production of maize intercropped with cowpea at seed ratio 70:30 followed by seed ratio 85:15 as compared to maize alone. However, no (p>0.05) difference was observed in TDN production among the three treatments. Four types of silages from, I) maize alone, II) maize and cowpea (85:15), III) maize and cowpea (70:30) and IV) maize supplemented with 2.5% urea were prepared. After 60 days of ensiling period, silage samples were analysed for proximate composition and fermentation characteristics. Crude protein and lactic acid values of silages I, II, III and IV were 8.52, 9.82, 14.90 and 13.96% and 9.00, 9.38, 10.86 and 7.43%; respectively. In situ dry matter digestibility was maximum in silage III followed by silages II, IV and I. The results suggested that intercropping of maize and cowpea at seed ratio 70:30 increased fodder production and produced quality silage.

THE SUBSTITUTABILITY OF MAIZE WITH CASSAVA ROOT AND LEAF MEAL MIXTURE IN BROILER DIETS

  • Ochetim, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.4
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    • pp.605-610
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    • 1992
  • Two experiments were conducted to investigate into the effects of replacing maize with a mixture of cassava root and leaf meal (CRLM) on the performance of broiler chickens. In experiment 1, CRLM replaced 50 or 100 percent of maize in the control diet. In experiment 2, the 100 percent CRLM based-diet was fortified at a further 3 percent level with coconut oil. A total of 180, one-day old Shaver Starbro chicks, raised up to 49 days of age, were used. There were no significant (p<0.05) differences in final body weights, feed intake and feed efficiency between the control group and the group fed the diet in which 50 percent of the maize was replaced with CRLM. At the 100 percent level of replacement of maize with CRLM, however, final body weights, feed efficiency and carcass yields, were significantly (p<0.05) reduced. Dressing percentage and feed intake were not affected (p>0.05) by level of substitution of maize with CRLM. In experiment 2, when the diet in which all of the maize was replaced with CRLM was fortified with coconut oil at an additional 3 percent level, broiler performance improved and equaled (p=0.05) that obtained on the control maize diet. It was concluded the CRLM can replace 50 percent of maize in broiler diet without adversely affecting performance. However, for the complete replacement of maize with CRLM, it is necessary to further supplement such a diet with a high energy density ingredient if broiler performance is to be maintained.

Effects of Ensiling Alfalfa with Whole-crop Maize on the Chemical Composition and Nutritive Value of Silage Mixtures

  • Ozturk, Durmus;Kizilsimsek, Mustafa;Kamalak, Adem;Canbolat, Onder;Ozkan, Cagri Ozgur
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.4
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    • pp.526-532
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    • 2006
  • The aim of this study was to evaluate the chemical composition, in vitro DM degradability, ME and OMD of alfalfa-maize silage mixtures in comparison to pure maize and alfalfa silages, and to test the existence of associative effects of ensiling alfalfa forage with whole-crop maize using the in vitro gas production technique. Ensiling alfalfa with whole-crop maize had a significant (p<0.001) effect on chemical composition, pH, in vitro DM degradability, OMD and estimated ME values of mixtures. DM content of the resultant silages significantly increased with increasing proportion of whole-crop maize in the mixtures, whereas the pH value, crude protein (CP), acid detergent fibre (ADF) and ash contents of mixtures decreased due to the dilution effect of whole-crop maize which was low in CP, ADF and ash. The pH values of all alfalfa-maize silage mixtures were at the desired level for quality silage. Gas production of alfalfa-maize silage mixtures at all incubation times except 12 h increased with increasing proportion of whole-crop maize. When alfalfa was mixed with whole-crop maize in the ratio 40:60, ME and OMD values were significantly (p<0.001) higher than other silages. Maximum gas production ($A_{gas}$) ranged from 65.7 to 78.1 with alfalfa silage showing the lowest maximum gas production. The results obtained in this study clearly showed that maximum gas production increased with increased percentage of whole-crop maize in the silage mixtures (r = 0.940, p<0.001). It was concluded that ensiling alfalfa with whole-crop maize improved the pH, OMD and ME values. However, trials with animals are required to see how these differences in silage mixtures affect animal performance.

Analysis of Genetic Diversity and Population Structure for Core Set of Waxy and Normal Maize Inbred Lines using SSR Markers (SSR 분자마커를 이용한 찰옥수수 및 종실용 옥수수 자식계통들의 핵심집단에 대한 유전적 다양성 및 집단구조 분석)

  • Sa, Kyu Jin;Kim, Jin-Ah;Park, Ki Jin;Park, Jong Yeol;Goh, Byeong Dae;Lee, Ju Kyong
    • Korean Journal of Breeding Science
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    • v.43 no.5
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    • pp.430-441
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    • 2011
  • Maize is divided into two types based on the starch composition of the endosperm in the seed, normal maize(or non-waxy maize) and waxy maize. In this study, genetic diversity and population structure were investigated among 80 waxy maize and normal inbred lines(40 waxy maize inbred lines and 40 normal maize inbred lines) using 50 SSR markers. A total of 242 alleles were identified at all the loci with an average of 4.84 and a range between 2 and 9 alleles per locus. The gene diversity values varied from 0.420 to 0.854 with an average of 0.654. The PIC values varied from 0.332 to 0.838 with an average of 0.602. To evaluate the population structure, STRUCTURE 2.2 program was employed to confirm genetic structure. The 80 waxy and normal maize inbred lines were separated with based on the membership probability threshold 0.8, and divided into groups I, II and admixed group. The 13 waxy maize inbred lines were assigned to group I. The 45 maize inbred lines including 7 waxy maize inbred lines and 38 normal maize inbred lines were assigned to group II. The 22 maize inbred lines with 20 waxy maize inbred lines and 2 normal maize inbred lines were contained in the admixed group. The cluster tree generated using the described SSR markers recognized three major groups at 31.7% genetic similarity. Group I included 40 waxy maize inbred lines and 11 normal maize inbred lines, and Group II included 27 normal maize inbred lines. Group III consist of only 2 normal maize inbred lines. The present study has demonstrated the utility of SSR analysis for the study of genetic diversity and the population structure among waxy and normal maize inbred lines. The information obtained from the present studies would be very useful for designing efficient maize breeding programs in Maize Experiment Station, Kangwon Agricultural Research and Extension Services.

Genetic Improvement of Maize by Marker-Assisted Breeding (분자마커를 활용한 옥수수 육종)

  • Kim, Jae Yoon;Moon, Jun-Cheol;Baek, Seong-Bum;Kwon, Young-Up;Song, Kitae;Lee, Byung-Moo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.59 no.2
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    • pp.109-127
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    • 2014
  • Maize is one of the most important food and feed crops in the world including Southeast Asia. In spite of numberous efforts with conventional breeding, the maize productions remain low and the loss of yields by drought and downy mildew are still severe in Asia. Genetic improvement of maize has been performed with molecular marker and genetic engineering. Because maize is one of the most widely studied crop for its own genome and has tremendous diversity and variant, maize is considered as a forefront crop in development and estimation of molecular markers for agricultural useful trait in genetics and breeding. Using QTL (Quantitative Trait Loci) and MAS (Marker Assisted Breeding), molecular breeders are able to accelerate the development of drought tolerance or downy mildew resistance maize genotype. The present paper overviews QTL/MAS approaches towards improvement of maize production against drought and downy mildew. We also discuss here the trends and importance of molecular marker and mapping population in maize breeding.

Variation of Univariate Flow Karyotypes and Chromosomal DNA Contents in Maize (Zea mays L.)

  • Lee, Jai-Heon;Lee, Myoung-Hoon;Kim, Kyung-Je
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.43 no.2
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    • pp.128-133
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    • 1998
  • Analyses of now karyotypes using different maize (Zea mays L.) inbred lines have been performed. The accumulation and isolation of high quality and quantity metaphase chromosomes from root tips can be achieved from many kinds of maize lines. The chromosome suspensions were prepared by a simple slicing method from synchronized maize root tips and analyzed with a now cytometry. The variations of experimental now karyotypes were detected among inbred lines in terms of the positions and/or the numbers of chromosome peaks. The 2C DNA amount among 8 inbred lines ranged from 5.09 to 5.52 pg. The variability of DNA content in maize chromosome 1 was 9.1 % ranging from 0.685 to 0.747 pg. The selection of appropriate maize lines is critical for sorting specific single chromosome types. At least five different chromosome types can be discriminated and sorted from five maize lines.

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Utilization of Korean Maizes in Prodction of Alkaline Processed Snack Foods

  • Lee, Jae-Kwon
    • Preventive Nutrition and Food Science
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    • v.2 no.1
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    • pp.11-16
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    • 1997
  • Alkaline cooking and processing properties of domestic maize were evaluated by comparing to those of imported control maize(Asgrow 404). Domestric maize varieties were hydrated more rapidly and had lower dry matter losses during alkaline cooking than control maize due to softer endosperm texture and incomplete removal of pericarps. Domestic maize varieties produced masas with proper handling properties when nixtamals had 50~52% moisture. However, masas produced from domestic maizes were puffed dur-ing baking and frying process due to the release of more free starch granules in the masa than control masa. Tortilla chips prepared from domestic maizes absorbed more oil during frying and had slightly higher water content with darker color than tortilla chips prepared from control maize. Among the domestic maize hybrids, KS42/Fla2BT113 had more acceptable kernel characteristics of tortilla chips than other varieties.

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