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.

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.

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.

옥수수에 있어서 다형현상에 관한 연구의 일환으로 Peroxidase 8에 대하여 수평전기 영동법에 의한 변이를 본 결과 중심주의 Peroxidase 8은 옥수수의 계통이나 품종에 따라 Fast, Slow, Fast/slow 밴드를 보여 주어 Peroxidase 8은 단일유전인자에 의하여 좌우된다고 생각되며 특히 본 연구에서 동일한 자식계통에 있어서도 상이한 밴드의 패턴을 보여주었는데 이는 사용한 계통이 동질접합체가 되지 못하였거나 혼종된 것이 아닌가 생각되어진다. 그러나 대가 자식계통의 옥수수는 Fast나 Slow의 단일 밴드패턴을 보여주었는데 반하여 단교잡 내지는 합성품종은 여러 가지 형태의 패턴을 보여주었다. 그리고 Peroxidase 8은 대개 초엽(중심주)이나 목화되지 않은 조직에서 흔히 관찰되나 Peroxidase 3와도 관계를 가지고 있는 것으로 생각되어진다. 특히 옥수수 줄기의 절에서 관찰되는 Peroxidase 3과 8의 패턴으로 보아 이 두 효소는 서로 상반되는 작용을 한다고 생각한다.

옥수수 생장발육의 한 Scheme을 작성하기 위하여 조생종 MIC-1과 만생종 수원 19호를 공시하여 1980년 4월 25일부터 6월 24일까지 12일 간격으로 6파종기를 두고, 휴폭 60cm에 주간 15cm로 파종하여 본시험을 실시하였다. 여기에서는 작물체의 주요기관 즉 엽, 기, 자종의 형태적 변화를 주로 조사하였으며 그 결과를 요약하면 다음과 같다. 1. 엽신의 발육을 그 전개정도에 따라 10등액으로 구분하여 Leaf Development Index(LDI)를 정의하였다. 2. 엽출현율(LAR)은 평균 3일로써 품종간, 재배시기간 큰 차가 없었다. 3. 출현 후 약 1개월 후에 절간이 신장하기 시작하여 절위별로 신장하며 지상부 제 1절이 벽출되는 시기는 제 8-9엽기에 해당되었다. 4. Silks의 형태적 변화는 종실의 발달과 밀접한 관계가 있었다(표 4참조). 5. 영양생장기간은 품종간 및 재배시기간에 차이가 현저하였지만 생식생장기간은 별차이가 없었다. 6. 완전전개된 엽수, 비대된 절수 그리고 Silks의 형태적 변화 및 종실발달 등으로 옥수수의 Scheme을 제시하였다.