促早栽培对杨梅叶片形态及果实成熟与品质的影响

Effects of forcing cultivation on the leaf morphology,fruit ripening and quality of Myrica rubra

【目的】探究促早栽培对杨梅叶片形态、果实成熟与品质的影响。【方法】以东魁和荸荠种杨梅为试材,设置双膜、单膜促早设施及露地三种不同栽培模式,连续监测不同栽培模式中的温度变化,调查试验地区的物候期,比较对应的有效积温和活动积温,并测定叶片表型和果实品质指标。【结果】与露地栽培相比,促早栽培设施中日平均气温和活动积温显著提高,其中双膜栽培作用更明显,活动积温达2592.1℃·d,提高74.3%;设施促早栽培下杨梅物候期和成熟期显著提前,双膜、单膜栽培杨梅成熟期分别比同地区的露地栽培提早40 d和22 d以上,采收期可长达57 d;设施促早栽培显著提高了单果质量、可溶性固形物含量和类黄酮含量等指标,商品果率提高1.6倍以上,经济效益显著提高。【结论】杨梅设施促早栽培技术是一种不影响杨梅正常生长,可显著提早成熟期、延长采收期、提升果实品质并大幅提高经济效益的栽培技术。

【Objective】Chinese bayberry(Myrica rubra) is an unique and valuable fruit crop cultured in southern China.As the most characteristic and prized fruit cultivated in Zhejiang province,it exhibits high levels of both nutritional benefits and economic value,which has significantly improved its market competitiveness.Main cultivated varieties of bayberry,like Dongkui and Biqizhong,mature from early June to early July.However,the bayberry during the maturation period usually encounters the rainy season,which results in severe decline in both yield and quality of bayberry,and further constrains the development of the bayberry industry.Thus,efforts to facilitate more reliable bayberry cultivation have the potential to improve its quality and output.Compared to traditional open-field cultivation,approaches to enhanced cultivation can increase temperatures and reduce the phenological periods for each stage of development,thus mitigating the potential harm caused by the plum rains.In addition,these approaches to protected cultivation can further improve commercial bayberry fruit outputs and promote its economic benefits.【Methods】In order to testify the benefits of protected cultivation for M.rubra,the leaf morphology,fruit ripening and quality of Biqizhong and Dongkui were studied,which were subjected to three different cultivation methods:open field(OF),single-layer-film-covered greenhouse(SLFG),and double-layer-film-covered greenhouse(DLFG).The cultivation of SLFG entailed the construction of a steel frame structure covered by a transparent plastic film based on the shape of the mountain slope,using triangular,arched,or flat roof multi-span steel frames as appropriate.The cultivation of DLFG entailed a novel and efficient cultivation method based on the use of SLFG triangular or arched roof multi-span steel frames on slopes,together with the introduction of a steel frame beam at a distance of 1.0 m from the top,followed by fixing a second transparent plastic film layer.After these protected cultivation models were established,temperature changes,phenological periods,and the relationships between temperature changes and phenological periods were assessed,and the leaf phenotypes and fruit quality were also measured.【Results】Compared to traditional OF cultivation,the average temperatures under DLFG and SLFG cultivation were 5.1 ℃ and 2.5 ℃ higher,respectively,significantly above the ambient temperatures.The forcing cultivation results in higher daily average temperatures,with a daily average temperature ≥ 10 ℃ lasting for 147 days under DLFG,as compared to 115days under DLFG and only 90 days under OF cultivation.The cumulative temperature under DLFG cultivation(2 592.1 ℃) also significantly increased,compared to SLFG and OF cultivation,with the increase reaching 74.3%.The phenological and maturation periods for M.rubra were significantly earlier under these forcing cultivations,with the maturation periods of DLFG and SLFG being 40 and 22 days earlier than those of OF cultivation.The harvest time under DLFG and SLFG cultivation was up to 57days,which was 3.4 times longer than that under OF cultivation.These forcing cultivation methods also significantly improved single fruit weight,soluble solid and flavonoid contents,taste,nutritional value,as well as storage and transportation capacity.Although these forcing cultivation methods reduced light intensity,the available light was sufficient to meet the needs for these bayberry trees.Thus,the normal plant growth and photosynthetic activity were not adversely impacted under either DLFG or SLFG cultivation.Moreover,the leaf morphology,including leaf length,width,area,perimeter,relative chlorophyll content,and chlorophyll fluorescence parameters increased with both Biqizhong and Dongkui.In addition,forcing cultivation significantly improved the fruit yields and quality.The results displayed that the average yields of Biqizhong under DLFG and SLFG cultivation were 2 312.5 kg · 666.7 m-2and2 261.7 kg · 666.7 m-2,respectively,40.0% and 37.0% higher than those under OF cultivation.Furthermore,the average commercial fruit rates were 85.1% and 79.8% under DLFG and SLFG cultivation,2.8-and 2.6-times higher than those under OF cultivation.Similarly,the average yields of Dongkui under DLFG and SLFG cultivation were 1 655.2 kg · 666.7 m-2and 1 568.5 kg · 666.7 m-2,respectively,2.9-and 2.8-times higher than those under OF cultivation.The commodity fruit rates and economic benefits surpassed 1.6-and 7.1-fold under DLFG and SLFG cultivation,respectively.【Conclusion】The forcing cultivation of M.rubra is an effective technique that can significantly advance the maturity period,extend the harvest period,improve fruit quality and promote economic benefits,without affecting the normal growth of M.rubra.Based on the above benefis of DLFG and SLFG cultivation,it is of a great value to further popularize and apply these bayberry cultivation techniques throughout China.