MITEs (miniature inverted-repeat transposable elements) are one of the major transposable elements in maize. We have applied MITE-AFLP technique to study the genetic diversity and genetic relationship among 25 elite maize inbred lines. While MITE-AFLP fra

Dehydrins (LEA Dll proteins) are one of the typical families of plant proteins that accumulate in response to dehydration, cold stress, abscisic acid, or during seed maturation. A 1.3-kb cDNA was cloned from a cDNA expression library of 5-day-old germinating maize scutellums under drought stress. The deduced protein sequence indicated a dehydrin gene encoding SK3 LEA protein typically expressed during cold acclimation, but not by drought stress in barley and wheat. Thus, it was named maize DEHYDRIN2 (ZmDhn2). It accumulates rapidly and highly in drought-stressed scutellum and leaf tissues at any stage, but not under cold stress. ZmDhn2 gene was transformed into Arabidopsis thaliana for functional analysis under drought condition. From electrolyte leakage test, no significant difference showed between wild type and transformants under normal growth condition, but the leakage level of electrolyte in wild type plants was about 3 times as high as that in the transformed plants under drought stress. It suggests that ZmDHN2 playa role in increasing drought tolerance.

Major characteristics of new Waesungri maize inbred line has multi-tiller and ears: five to six tillers and seven to eight ears per plant and flowering date of Waesungri was delayed about 18 and 24 days compared to Mo17 U.S line and IK4 Korean local lines, respectively. Number of ears, fresh and dry weight per plant were significantly different among all tested hybrids including Waesungri/Sinkihong hybrid under different planting times and densities. Especially, both fresh and dry weight of IK1/FR140//Waesungri F1hybrid were significantly higher at high planting density. In kernel weight per unit area, Wnesungri/Sinkihong hybrid was high at high density and IK1/FR140//Waesungri hybrid was high at low planting density. As results of analysis of variance, flowering date was shown a significantly different both planting times and varieties, while other characters including stem height were shown very variable in interactions with enviromental factors.

Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ha-1 ) and four levels of potassium (0, 40, 80 and 120kg K2 O ha-1 ) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg K2 O ha-1

In nature, plant diseases, insects and parasites (hereafter called as "pest") must be co-survived. The most common expression of co-survival of a host crop to the pest can be tolerance. With tolerance, chemical uses can be minimized and it protects environment and sustains host productivity and the minimum pest survival. Tolerance can be applicable in all living organisms including crop plants, lifestocks and even human beings. Tolerant system controls pest about 90 to 95% (this pest control system often be called as horizontal or partial resistance), while the use of chemicals or selection of high resistance controls pest 100% (the most expression of this control system is vertical resistance or true resistance). Controlling or eliminating the pests by either chemicals or vertical resistance create new problems in nature and destroy the co-survial balance of pest and host. Controlling pests through tolerance can only permit co-survive of pests and hosts. Tolerance is durable and environmentally-friend. Crop cultivars based on tolerance system are different from those developed by genetically modified organism (GMO) system. The former stabilizes genetic balance of a pest and a host crop in nature while the latter destabilizes the genetic balance due to 100% control. For three decades, the author has implemented the tolerance system in breeding maize cultivars against various pests in both tropical and temperate environments. Parasitic weed Striga species known as the greatest biological problem in agriculture has even been controlled through this system. The final effect of the tolerance can be an integrated genetic pest management (IGPM) without any chemical uses and it makes co-survival of pests in nature.in nature.

분얼형 옥수수인 4개 교잡종과 대조구인 P3394 교잡종과의 수량특성을 비교한 결과는 다음과 같다. 1. 생초수량에 대하여 재식밀도별로 알아보면 4,800주/10a에서는 PI213749//FR805/IK3 교잡종이 7,862kg이고, FR805/IK3//Waesungri 교잡종이 8,290kg/10이며, IK/LE//FR805/IK3 교잡종이 7,746kg/10a로서 대조구인 P3394의 6,247kg/10a보다도 많았다. 2. 건물수량은 대조구인 P3394 교잡종이 4,800주/10a에서 1,430kg로 다른 분얼형 옥수수 교잡종인 PI213749//FR805/IK3은 1,834kg/10a FR805/IK3//Waesungri 교잡종이 1,836kg/10a, IK/LE//FR805/IK3 교잡종이 1,810kg/10a로 많았다. 3. 종실수량은 4,800주/10a에서 IK/LE//FR805/IK3 교잡종이 783kg로 대조구인 P3394의 776kg/10a 보다 많았으며, 3,600주/10a에서는 대조구에서 714kg/10a로 다른 분얼형 옥수수 교잡종보다 종실수량이 많았다. 그러나 2,400주/10a에서는 오히려 분얼형 옥수수 교잡종인 IK/LE//FR805/IK3 교잡종이 752kg/10a이고, PI213749/Dangjin//FR805/IK3 교잡종이 699kg/10a로서 대조구인 P3394의 680kg/10a 보다 높았다.

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.

Carotenoid compounds in embryos of wild-type(WT) and viviparous mutants of maize(Zea mays L.) were analyzed using high performance liquid ehromatography (HPLC) with a photodiode array detector. Zeaxanthin accumulates in WT embryos as the major carotenoid. Phytoene accumulates in vp2 and vp5. Phytofluene in w3 and ζ-carotene in the vp9 mutant embryos. This indicates that the vp2 and vp5 mutants impair phytoene desaturase from 15-cis-phytoene to 15-cis-phytofluene. The w3 mutant has neither an isomerase from 15-cis-phytofluene to all-trans-phytofuene nor phytofluene desaturase from phytofluene to ζ-carotene. The vp9 mutant does not have the ζ-carotene desaturase from ζ-carotene to lycopene. Our analysis shows that the terminal carotenoid. γ-carotene(β,ψ-carotene), accumulates in the vp7 mutant embryos. The ε-carotene(ε,ε-carotene), a product of δ-carotene(ε,ψ-carotene) in some plants, however, has not been found in maize embryos. The vp7 mutant impairs a cyclization step from γ-carotene to both β-carotene and α-carotene. We suggest that monocyclic γ-carotene is the sole precursor of both bicyclic β-carotene(β,β-carotene) and α-carotene(β,ε-carotene) in maize.

한국 재래종 옥수수의 염색체 특성을 알아보기 위하여 재래종 옥수수 10개의 자식계통 C-banding법으로 염색하고 염색체상에 존재하는 heterochromatic knob 수를 조사한 결과는 다음과 같았다. 1. Knob수는 6∼12개이었고 평균 9.0개이었으며 계통별로 차이가 있었다. 2. 염색체의 장완과 단완의 비율, 상대적 길이 등을 비교해 보기 위하여 Waesungri와 PI213-749 두 계통을 조사해 본 결과 계통별로 차이가 있었다. 즉, 장완과 단완의 비율은 2번 염색체의 경우에만 1.25로서 동일하였고 다른 염색체의 경우는 모두가 다르게 나타났다. 염색체의 상대적 길이는 일반적으로 Waesungri에서 크게 나타났는데 1번 염색체의 경우 Waesungri에서는 223이었고 PI213749에서는 192이었다. 3. 염색체의 상대적 길이, 장완과 단완의 비율, 그리고 knob의 위치 등을 나타내는 모식도를 통하여 두 계통의 염색체 특성을 보다 명확하게 비교할 수 있었다.

The objective of this report is to review the up to present papers including 79 references about functional ingredients in maize and their variations. Maize is a good source of such antioxidants as α-,~;~gamma-tocopherols,~;α-,~;β-carotene,~;β-cryptoxanthin , zeaxanthin, quercetin and chlorogenic acid. Unsaponifiable standard extracts of Zea mays L. (ZML) have a beneficial effect on various dental diseases. Flavonoids, flavonoid biosynthetic pathway and their controling genes were also reviewed in this report. Flavonoids are required for successful fertilization in maize pollen, and maysin has a potent antibiotic activities to earworm and fall armyworm in maize silks. Maize silks have been used in traditional medicine for diuretic, vascular diseases and diabetes, etc. and boiling water extracts of maize silk have hemodynamic effects, but their ingredients still remain obscure.

Giemsa C-banding 방법에 의하여 한국 재래종 옥수수 핵형 및 염색체의 특성을 알아보고자 옥수수의 근단 생장점을 이용하여 조사 분석하였다. 이 방법은 한국 재래종 옥수수의 핵형 분석 및 염색체의 특성 연구에도 효과적으로 활용할 수 있는 방법임이 확인되었다. 조사된 재래종 옥수수에서는 각각 10개의 heterochrornatic knob이 발견되었으며 이것들의 크기와 위치는 계통별로 다른 것으로 나타났고, 모두가 6번 염색체에 부수체를 가지고 있었다. 10번 염색체를 100으로 해서 비교해 본 각 염색체들의 상대적 길이는 조사된 계통별로 큰 차이가 있었다.

The effects of plant hormones (NAA, GA3 and BA) and light qualities (white, red, green and blue light) on the changes of reducing sugar contents and invertase isozyme activities in leaves of maize (Zea mays L.) and mung bean (Phaseolus radiatus L.) seedlings were investigated. NAA accelerated the increase of reducing sugar contents and invertase isozyme activities, on the contrary, GA3 had little effect in the accumulation of reducing sugar and in the increase of enzyme activities from the leaves of maize and mung bean seedlings. On the other hand, BA accelerated an increase in the activities of the invertase isozyme from the leaves of mung bean seedlings whereas it had little effect in the increase of the enzyme activities from those of maize seedlings. The accumulation of reducing sugar in leaves of both seedlings was promoted by red light irradiation compared to white light irradiation, while the activities of the enzyme were little affected by various light qualities. In the simultaneous applications of plant hormone and light quality, NAA with white light was very effective in the increase of reducing sugar contents and the enzyme activities from the leaves of mung bean seedlings, whereas NAA application with blue light showed a prominent enhancement in the reducing sugar contents and the enzyme activities from those of maize seedlings. These results suggest that plant hormone, particularly NAA, may be a more important factor than various light qualities in the stimulation of invertase activity.

6개 자식계통 찰옥수수에 의한 이면교배 조합(역교배 불포함)에 대하여 식물학적 특성과 이삭 관련 특성들에 대하여 조사한 것을 요약하면 다음과 같다. 1. 6개 자식계통들의 개화기, 간장, 착수고, 엽면적 및 수경의 길이는 각 계통들 간에 차이가 있었다. 특히 보성 계통의 수경길이가 24.4cm였는데 반하여 칠보 계통은 9cm에 불과하였다. 2. 6개 자식계통들의 이삭길이, 이삭직경, 100립중, 이삭속길이, 열수 및 이삭당 립수 등 역시 계통간에 큰 차이가 있었다. 특히 보성 계통은 이삭 길이가 13.4cm로 계통 중 가장 컸으나 이삭 직경과 열수와 이삭당 총 당수가 가장 낮았으며, 100립종은 가장 무거웠다. 반면 당진 계통은 이삭 길이가 9.3cm로 짧은 대신에 이삭직경이 크고, 또 열수도 비교적 많아 이삭당 당수가 282개로 가장 많았다. 3. 자식계통들의 10a당 곡실 수량을 보면 분얼을 하고 다수성인 제원 계통이 285kg으로 가장 많았다. 4. 15개 교잡종들이 자식계통 특성 가운데 개화기, 간장, 착수고, 엽면적 등은 교배조합에 따라 큰 차이를 보였다. 5. 15개 교잡종들의 이삭관련 특성을 보면 보성 계통을 양친으로 한 조합들은 이삭길이가 길었고 100립종도 무거웠다. 반면에 당진 계통의 교잡종들은 이삭길이가 짧았다. 6.풋옥수수 수량이 높았던 것은 보성 계통과 교배된 조합들 이었으나, 곡실수량에서는 당진과 교배된 조합들이었다. 7. 당진계통의 일반조합능력은 교잡종의 간장과 착수고를 낮게 하는데 효과적이었다. 8. 제원계통은 교잡종들의 분얼수를 증가시키는 방향으로 일반조합능력이 컸다. 9. 이삭의 길이, 100립종, 열수 등 이삭 관련 형질에 대한 일반조합능력 효과는 보성 계통이 컸고, 종실 수량에 대한 일반조합능력이 컸던 계통은 제원과 단양 계통이었다. 10. 이삭의 길이, 100립종 등에 대한 특수능력이 컸던 조합은 제원/칠보조합이었고, 종실 수량에 대한 특수조합능력이 컸던 계통은 보성/당진이었다.