• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.4
• /
• pp.605-610
• /
• 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.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.2
• /
• pp.128-133
• /
• 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.

• Korean Journal of Agricultural Science
• /
• v.44 no.2
• /
• pp.196-210
• /
• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.

• Korean Journal of Medicinal Crop Science
• /
• v.27 no.4
• /
• pp.284-291
• /
• 2019

Background: Ginseng root rot disease, caused by Cylindrocarpon destructans and Fusarium solani is a major cause of replant failure in continuous cropping ginseng. Methods and Results: To control replant injury in soil infected with C. destructans and F. solani, biosolarization was performed by covering the plot with transparent polyethylene film after adding green manure of maize and sunflower for the summer season. Per 10 a, fresh and dry weight of maize was 10.1 and 2.5 tons, respectively, and that of sunflower was 8.1 tons and 1.2 tons, respectively. Mean maximum temperature at 20 cm depth was $33.2^{\circ}C$, $41.5^{\circ}C$ and $41.8^{\circ}C$ in the control, maize-incorporated and sunflower-incorporated plots, respectively. The elapsed time over $40^{\circ}C$ was 36.4 h in the maize-incorporated plot and 77.3 h in the sunflower-incorporated plot. Biosolarization increased $NO_3$ content in soil, while content of organic matter, Ca, and Mg was decreased. Electrical conductivity, $NO_3$ and $P_2O_5$ in soil significantly increased after two years of biosolarization. The number of spores of C. destructans in soil was significantly decreased by biosolarization, and sunflower treatment was more effective than maize treatment in decreasing the number of spores. Root yield of 3-year-old ginseng was significantly increased by biosolarization, however, there was no significant difference between maize and sunflower treatments. Rate of root rot in 3-year-old ginseng decreased to 16.5% with the incorporation maize and 5.0% with the incorporation of sunflower, while that in control 25.6%. Conclusions: Biosolarization was effective in inhibiting ginseng root rot by decreasing the density of root rot disease and improving soil chemical properties.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.6
• /
• pp.585-593
• /
• 1994

This study was conducted to know optimum ground water level for maize(Suwon 19) and sorghum-sudangrass hybrid(Pioneer855F) and investigated effect of different soil types and ground water levels on growth of above two crops at containers were controlled so as to be 25, 35, 50, 70 and 100cm from the soil surface. Both crops showed better growth in sandy loam soil. Optimum ground water level for maize was l00cm and for sorghum-sudangrass hybrid was 70cm in sandy loam soil. Clay loam was unfavorable for both crops even though low ground water level maintained. Sorghum-sudangrass hybrid was adapted better to clay loam soil and high ground water levels. In microscopic study on root anatomy of both crops, destructed cortical tissues were observed. Frequency of the tissues was higher in maize than in sorghum-sudangrass hybrid and higher at mid or tip parts than basal parts of roots in both crops. Arrangement of cortical cells of roots in sorghum-sudangrass hybrid were more regular than those of maize. In root anatomy, no consistent trend with soil types or ground water levels was detcted.

• Journal of Crop Science and Biotechnology
• /
• v.10 no.2
• /
• pp.57-63
• /
• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• Journal of Life Science
• /
• v.20 no.2
• /
• pp.298-303
• /
• 2010

In this work, the effects of $Cs^+$ on root growth of 2-day-old maize seedlings were scrutinized. CsCl (5 mM - 30 mM) decreased the fresh weight of the primary root and of the shoot above the coleoptilar node. The elongation growth of the primary root was also inhibited by CsCl. The CsCl-inhibited growth was partially restored by 60 mM KCl. Lineweaver-Burk plot of the reaction in the presence and absence of 60 mM KCl displayed competitive interaction of CsCl (at higher than 10 mM). However, the Reversal of the inhibition by 60 mM KCl did not follow the competitive relationship with 5 mM CsCl, indicating the presence of differential mechanisms of $K^+$ influence depending on the concentration of CsCl. The differential effects of CsCl dependent on the concentrations were also observed in the CsCl-evoked radial expansion of the subapical region of the root. In spite of the decrease in length of the root, shrinkage of the root apical meristem was not observed. CsCl above 10 mM induced the expression of ZmKUP1, indicating functional deficiency of $K^+$ due to competition with Cs. However, the expression of ZmKUP1 by 5 mM CsCl was unclear. Conclusively, exogenously applied $Cs^+$ decreased root elongation and fresh weight and caused radial expansion of the subapical region of the primary root in 2-day-old maize seedlings by complex mechanisms including competitive and noncompetitive interactions with $K^+$. Because the shrinkage of the root apical meristem was not observed, it is concluded that the effects of CsCl on maize root growth was mainly related to cell expansion.

• BMB Reports
• /
• v.28 no.3
• /
• pp.227-231
• /
• 1995

In order to figure out the relationships between structural features and biological activity of the host-specific HC-toxin in maize, structurally related cyclic tetrapeptides, chlamydocin and CYL-2 were isolated, and their biological activities in maize were examined. Biological activities of preparations were determined by root growth inhibition and electrolyte leakage bioassays. Chlamydocin and CYL-2 showed toxicities to maize. However, the toxicities of these compounds were non-specific. Thus, the precise peptide ring structure of HC-toxin apparently does not play an important role in toxicity, while resistance of maize to HC-toxin is based on a precise ring conformation.

• Korean Journal of Medicinal Crop Science
• /
• v.26 no.3
• /
• pp.248-253
• /
• 2018

Background: Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds. Methods and Results: The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. After May fumigation, the sowing date of maize was delayed by 15 days and thus its dry weight was decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, $NO_3$, $P_2O_5$, and K significantly. Maize cultivation after May fumigation decreased fungi population and the ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different between treatment of May and September, but Fusarium solani showed a significant increase in September fumigation after maize cultivation. Conclusions: Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by the amendment of mineral composition and microorganism in fumigated soil.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1999.05a
• /
• pp.162-163
• /
• 1999

The goal of this research was (1) to describe the conditions and parameters required for the cell cycle synchronization and the accumulation of large number of metaphase cells in maize and other cereal root tips, (2) to isolate intact metaphase chromosomes from root tips suitable for characterization by flow cytometry, and (3) to construct chromosome-specific libraries from maize. Plant metaphase chromosomes have been successfully synchronized and isolated from many cereal root-tips. DNA synthesis inhibitor (hydroxyurea) was used to synchronize cell cycle, follwed by treatement with trifluralin to accumulate metaphase chromosomes. Maize flow karyotypes show substantial variation among inbred lines. thish variation should be sueful in isolating individual chromosome types. In addition, flow cytometry is a useful method to measure DNA content of individual chromosomes in a genotyps, and to detect chromosomal variations. Individual chromosome peaks have been sorted from the maize hybrid B73/Mol7. Libraries were generated form the DOP-PCR amplification product from each peak. To date, we have analyzed clones from a library constructed from the maize chromosome 1 peak. Hybridization of labeled genomic DNA to clone inserts indicated that $24\%,\;18\%,\;and\;58\%$ of the clones were highly repetitive, medium repetitive, and low copy, respectively. Fifty percent of putative low cpoy clones showed single bands on inbred screening, blots, and the remaining $50\%$ were low copy repeats. Single copy clones showing polymorphism will be mapped using recombinant inbred mapping populations. Repetitive clones are being characterized by Southern blot analysis, and will be screened by in situ hybridization for their potential utility as chromosome specific markers.