鈣與硼對番茄果實品質之影響

Abstract

番茄 (Solanum lycopersicum L.) 為世界重要經濟作物，然而在番茄商業生產區常有缺鈣相關生理障害-尻腐病 (blossom-end rot, BER) 的發生並造成經濟損失。因此如何防治番茄果實遭遇尻腐病成為重要的任務。葉面噴撒 0.5% 氯化鈣溶液為常用的尻腐病防治對策但耗費人力。之前研究顯示調整水耕試驗中營養元素比例也可降低尻腐病發生率，但與臺灣現行番茄常用的介質耕方式有所差異。且少有研究探討營養元素處理可能造成不同品種間尻腐病發生率存在差異性。因此本研究針對不同商用大果番茄探討介質耕時養液鈣與硼濃度對尻腐病發生率與嚴重度、營養元素濃度、果實產量與品質的影響。 於2013年9月至2015年4月期間進行三次試驗，分別是試驗一：2013年冬作鈣試驗 (0.5mM、1.0mM、2.0mM) 、試驗二：2014年夏作硼試驗 (30.0μM、45.0μM 、67.5μM、101.0μM) 及試驗三：2014年冬作硼試驗 (25μM、50μM、100μM)。 試驗一結果顯示，十個番茄品種於不同鈣濃度養液處理下具有不同外部尻腐病發生率，藉此選出 ‘美惠’、‘種苗亞蔬15號’、‘金剛二號’、‘鐵娘’及‘CLN2460L’五個品種進行後續果實產量、品質及營養元素分析。養液中鈣濃度高低並不顯著影響五品種之細胞膜滲漏度、產量、可溶性固形物含量、可滴定酸含量、糖酸比、細胞間液之鈣濃度，但葉片與果實中的營養元素濃度則受番茄品種、養液鈣濃度等因素所影響。 試驗二結果顯示尻腐病發生率不受養液中硼濃度處理所影響，但‘CLN2460L’ 生長在45μM硼養液濃度下有顯著最低之外部尻腐病嚴重度與總尻腐病嚴重度。養液中硼濃度高低並不顯著影響各品種之硬度、抗壞血酸含量、單果重與總產量。‘種苗亞蔬15號’之果實鈣、硼元素濃度受到硼養液濃度影響，分別在67.5μM、101.0μM處理時濃度達最高，‘金剛二號’及‘CLN2460L’果實鉀、鎂、鈣、磷等濃度則都不受養液硼濃度所影響。 試驗三結果顯示，‘CLN2460L’ 在50μM硼濃度處理時，有顯著最低的總尻腐病嚴重度，此結果與試驗二的45μM硼濃度處理相似。養液中硼濃度高低並不顯著影響各品種之可溶性固形物含量、可滴定酸含量、糖酸比、抗壞血酸含量與總產量。提高養液硼濃度顯著增加‘美惠’、‘種苗亞蔬15號’與‘CLN2460L’葉片中硼濃度。‘種苗亞蔬15號’之果實硼濃度在100.0μM養液硼濃度處理時濃度最高，此點與試驗二該品種在101.0μM處理時有最高果實硼濃度結果相似。 綜合以上，本研究建立外部和內部尻腐病徵狀的分級標準，雖然無論哪種養液硼濃度處理都無法顯著降低尻腐病發生率，但45μM~50μM養液硼濃度處理的確可以顯著降低‘CLN2460L’尻腐病嚴重度。

Abstract Tomato (Solanum lycopersicum L.) is an important economic crop worldwide. However, blossom-end rot (BER), a calcium-related physiological disorder, occurs frequently in tomato commercial production areas and causes financial loss. Therefore, figuring out the way to prevent tomato fruits from BER is an important task. Foliar spray of 0.5% CaCl2 is a common approach for preventing BER but laborious. Previous study also showed that adjusting the concentrations of mineral elements in hydroponic solution can lower the BER incidence. In Taiwan, however, we usually grow tomato plants by substrate culture rather than hydroponic culture. Furthermore, few researches discussed about the possible BER incidence difference among cultivars in response to mineral element treatments. Thus, this research studied on the effects of calcium and boron concentrations in nutrient solution on BER incidence, BER severity, concentrations of mineral elements, as well as fruit yield and quality of different commercial tomato cultivars grown by substrate culture. During September 2014 to April 2015, three experiments were performed, including experiment I: calcium concentration (0.5mM/1.0mM/2.0mM) treatments during 2013 winter; experiment II: boron concentration (30.0μM/45.0μM/67.5μM/101.0μM) treatments during 2014 summer; experiment III: boron concentration (25μM/50μM/100μM) treatments during 2014 winter. The results in experiment I showed that ten tomato cultivars displayed different external BER incidence when grown with nutrient solution containing different calcium concentrations. Accordingly, we selected ‘Mei Huei’, ‘Taiwan Seed ASVEG #15’, ‘King Kong 2’, ‘Tie Niang’ and ‘CLN2460L’ for further fruit yield, fruit quality and mineral element analyses. Calcium concentration in nutrient solution did not significantly affect the electrolyte leakage (EC), yield, total soluble solids content (TSS), titratable acidity, oBrix:acidity ratio, apoplastic calcium concentration in all the five cultivars, but leaf and fruit mineral elements concentrations varied depending on the tomato cultivar and the calcium concentration in nutrient solution. The results in experiment II showed that BER incidence seemed to be independent of the boron concentration in nutrient solution, but ‘CLN2460L’ had lowest external BER severity and total BER severity when grown with nutrient solution containing 45μM boron. Boron concentration in nutrient solution did not significantly affect the firmness, ascorbic acid content, single fruit weight and total yield. ‘Taiwan Seed ASVEG #15’ had highest fruit calcium and boron concentrations when grown with nutrient solution containing 67.5μΜ and 101.0μΜ boron, respectively. However, fruit K, Mg, Ca, and P concentrations of ‘King Kong 2’ and ‘CLN2460L’ appeared to be independent of the boron concentration in nutrient solution. The results in experiment III showed that ‘CLN2460L’ had lowest total BER severity when grown with nutrient solution containing 50μM boron, which is similar to the results in experiments II when ‘CLN2460L’ were grown with nutrient solution containing 45μM boron. Boron concentration in nutrient solution did not significantly affect the TSS, titratable acidity, oBrix:acidity ratio, ascorbic acid content and total yield. Leaf boron concentrations were significantly increased in ‘Mei Huei’, ‘Taiwan Seed ASVEG #15’ and ‘CLN2460L’ when boron concentration in nutrient solution was increased. ‘Taiwan Seed ASVEG #15’ had highest fruit boron concentration when grown with nutrient solution containing 100.0μM boron, which is similar to the results in experiments II when ‘Taiwan Seed ASVEG #15’ was grown with nutrient solution containing 101.0μM boron. In conclusion, this research developed a standard for rating the external and internal BER symptoms. Even though treatment of tomato plant with nutrient solution containing any one of the given boron concentrations cannot significantly reduce BER incidence, ‘CLN2460L’ had significantly lower BER severity when grown with nutrient solution containing 45~50μM boron.