淹水對苜蓿產量、品質及根部組織之影響

苜蓿（Medicago sativa L.）為多年生之重要豆科芻料作物，在雨季常因淹水而生長不良，為探討台灣地區春、夏不同季節栽培時，淹水對不同苜蓿品種生育之影響，本試驗以台灣常用引進品種中東苜蓿（Middle East alfalfa）及Hunter River苜蓿種子為材料，分別於二月及五月種植，分別於4葉期、8葉期及盛花期時淹水10天，並以不淹水處理為對照（CK）。結果顯示春季淹水對產量影響不明顯，夏季淹水對產量則有極大之影響，中東苜蓿不同生育期淹水鮮草產量由2537.3 kgha^(-1)～3904.3 kgha^(-1)，低於對照組之5525.0 kgha^(-1)，Hunter River淹水處理之鮮草產量1254.3～1637.7 kgha^(-1)亦低於對照之4342.7 kgha^(-1)。淹水亦影響鎂、鉀、鈣、酸洗纖維（acid detergent fibre, ADF）及中洗纖維（neutral detergent fibre, NDF）等組成分之變化，尤其粗蛋白質於淹水後有下降之趨勢，如於夏季開花期淹水處理Hunter River及中東苜蓿之粗蛋白質分別為14.16%及13.7%，遠低於對照處理之17.6%及16.67%。藉由根的石蠟切片技術及正立顯微鏡觀察，發現4葉期及8葉期淹水對根組織傷害最嚴重，經由偏光顯微鏡觀察得知，淹水同時會影響根部澱粉的累積。綜合上述結果，Hunter River及中東苜蓿於不同生育期淹水，以4葉期及8葉期之淹水較盛花期影響為大，夏季淹水影響較春季為大，夏季栽培於各生育時期之淹水均會影響苜蓿生育，進而影響品質及產量。

關鍵字

苜蓿；淹水；生育；組織學

並列摘要

Alfalfa(Madicago sativa L.)is an important perennial forage legume for dairy cows in Taiwan. Growth of alfalfa is inhibited when it is waterlogged. The objective of this study was to determine the effect of waterlogging on forage yield, quality and root histology of alfalfa. In this study, cv. Hunter River and Middle East were used. The plants were waterlogging at 4^(th) leaf, 8^(th) leaf and blooming stages, each for 10 days both in spring and summer crops. The non-waterlogging treatment was used as control (CK). The results showed that no significant effects were observed on forage yield or agronomic traits by waterlogging in spring crop. However, in summer crop there were obvirous effects on forage yield after 10 days of waterlogging in each growth stages. Forage yields of waterlogged Middle East ranged from 2537.3 to 3904.3 kgha^(-1), comparing to the control, 5525.0 kgha^(-1), while those of the Hunter River ranged from 1254.3 to 1637.7 kgha^(-1) by waterlogging at different growth stages when compared to the control of 4342.7 kgha^(-1). The contents of P, Mg, K, Ca, ADF and NDF of alfalfa were also affected by waterlogging. Serious damage was observed in root tissue waterlogged at 4^(th) and 8^(th) stages. The carbohydrate sink in the roots was also affected by waterlogging. More significant effects were observed when waterlogged at 4^(th) and 8^(th) leaf stage than at blooming stage for both in spring crop. In summer crop, the growth of alfalfa was affected more seriously by waterlogging at different growth stages. Further, forage yield, quality and roots histology of alfalfa were badly affected.

並列關鍵字

Alfalfa (Medicago sativa L.) ； Waterlogging ； Growth ； Histology

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