Drought Resistance of Several Soybean Cultivars

주요대두품종(主要大豆品種)의 내건성(耐乾性)에 관(關)한 연구(硏究)

Twelve soybean cultivars were cultivated in the 1/2,000a. Wagner pots with irrigation and without irrigation for 30 days after flowering, and the differences of plant growth and bean yield among cultivars were compared. And to investigate the varietal differences in the rate of photosynthesis under different relative humidity, 6soybean cultivars were cultivated in 1/2,000a. Wagner pot and the rate of photosynthesis of each soybean cultivar at flowering time was measured under the relative humidity of 80, 70, 60, 50 and 40%. The results obtained are summarized as follows; 1. The days to maturity of the soybean cultivars were shortened by non-irrigation treatment. The response of the maturing dates to non-irrigation was significantly different among the soybean cultivars. The days for maturing of Paldal, Danyeob and Eundaedu were delayed 2 days but those of Jangbaek and Tamahomare were delayed about 7 to 8 days under non-irrigation treatment. 2. The stem length, stem diameter, number of nodes of the mainstem, number of branches and number of branch nodes of all soybean cultivars were decreased by non-irrigation treatment. The number of branches and the number of branch nodes were especially severely influenced by non-irrigation treatment. 3. The number of pods per plant and the number of perfect pods was significantly reduced by non-irrigation treatment but the number of imperfect pods was increased. The non-irrigation treatment reduced the number of pods per plant by 58.0% and the ratio of the number of the perfect pods per plant by 46.6% relative to the ordinary cultivation with irrigation. 4. The grain yield of all cultivars was significantly reduced by the non-irrigation treatment, and average grain yield of soybean cultivars cultivated under non-irrigation treatment was 35.9% of that of soybean cultivars cultivated with irrigation. The influence of non-irrigation treatment was lowest in Paldal and significantly high in Tamahomare and Jangbaek. 5. The rate of photosynthesis of soybean leaves was significantly different among cultivars and was also influenced by relative humidity. Ratio of the photosynthetic amount of soybean leaves at 40% RH to the maximum photosynthesis at optimal humidity was 97.2% in Paldal, 96.4% in Danyeob and 88.8% in Baekun. 6. At 40% relative air humidity, highly significant correlations were found among the photosynthesis rate, the amount of transpiration and the respiration rate.

본(本) 실험(實驗)은 1/2,000a Wagner pot에 12개(個) 대두(大豆) 품종(品種)을 재배(栽培)하면서 관수(灌水)와 개화후(開花後) 30일간(日間)의 무관수처리(無灌水處理)에 따른 생육(生育) 및 수량(收量)을 품종별(品種別)로 비교(比較)하였으며 6개(個) 대두품종(大豆品種)을 1/2,000a Wagner pot에 재배(栽培)하여 개화기(開花期)에 대기습도(大氣濕度) 80, 70, 60, 50 및 40%에서의 광합성속도(光合成速度)의 품종간(品種間) 차이(差異)를 조사(調査)하였는데 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 모든 품종(品種)의 성숙일수(成熟日數)는 무관수처리(無灌水處理)에 의하여 단축(短縮)되었는데 그 정도(程度)는 품종(品種)에 따라서 상이(相異)하여 팔달(八達)콩, 단엽(短葉)콩 및 은대두(銀大豆)는 2일간(日間) 장백(長白)콩은 7일(日) 그리고 다마호마레는 8일간(日間)이나 단축(短縮)되었다. 2. 간장(桿長), 경직경(莖直徑), 주경절수(主莖節數), 분가수(分柯數) 및 분가절수(分柯節數)등은 모든 품종(品種)이 건조처리(乾燥處理)에 의하여 감소(減少)하였는데 특(特)히 분가수(分柯數)와 분가절수(分柯節數)는 무관수처리(無灌水處理)의 영향(影響)이 현저하였다. 3. 주당협수(株當莢數)와 완전협수(完全莢數)는 무관수처리(無灌水處理)에 의하여 현저히 감소(減少)하였는데 반(反)하여 불완전협수(不完全莢數)는 증가(增加)하는 경향(碩向)이었으며 관수처리(灌水處理)에 대(對)한 무관수처리(無灌水處理)의 주당협수(株當莢數)는 전체품종(全體品種) 평균(平均)이 58.0% 그리고 완전협수(完全莢數)는 46.6%이었다. 4. 주당입중(株當粒重)은 모든 품종(品種)이 무관수처리(無灌水處理)에 의하여 크게 감소(減少)하여 전체품종(全體品種) 평균(平均)이 관수처리(灌水處理)의 35.9%에 불과(不過)하였는데 팔달(八達)콩은 무관수처리(無灌水處理)의 영향(影響)이 가장 적었고 다마호마레와 장백(長白)콩은 무관수처리(無灌水處理)의 영향(影響)이 현저하였다. 5. 대기습도(大氣濕度)에 따른 광합성속도(光合成速度)는 습도(濕度) 및 품종간(品種間)에 차이(差異)가 나타났으며 품종별(品種別) 최고(最高) 광합성치(光合成値)에 대(對)한 대기습도(大氣濕度) 40%에서의 광합성속도(光合成速度)의 비율(比率)은 팔달(八達)콩이 97.2%, 단엽(短棄)콩이 96.4%이었고 백운(白雲)콩은 88.8%이었다. 6. 대기습도(大氣濕度) 40%에서의 광합성속도(光合成速度)와 증산(蒸散) 및 뿌리의 호흡속도간(呼吸速度間)에는 높은 정상관관계(正相關關係)가 인정(認定)되었다.