8 Fruit Mulberry Varieties Quoted Adaptive Evaluation In The Yulin Area

Fruit mulberry is a type of mulberry that produces edible fruits and leaves.It can be cultivated in the northeast,northwest and north regions of China.Yulin area,located at the transition zone between Mu Us Sandy Land and Loess Plateau,has a suitable geographic latitude and climate environment for fruit mulberry.However,the existing mulberry varieties in this region are relatively homogeneous and have low fruit quality.Therefore,we conducted introduction experiments of eight different fruit mulberry varieties in Yulin area and analyzed their phenology,growth characteristics,nutritional quality and photosynthetic physiological characteristics.We used the membership function method to evaluate the adaptability of these varieties based on their growth characteristics,photosynthetic physiological indices and nutritional indices.The aim of this study was to provide a biological basis for introducing excellent fruit mulberry varieties in Yulin area and to offer scientific and theoretical support for selecting suitable mulberry varieties for cultivation and large-scale development in this region.The main results are as follows:（1）The eight mulberry varieties have different growth stages,but they can all grow,flower and fruit normally in this area and complete their life cycle.Generally,they germinate in late February,their leaves expand in late March and they flower in early April.At the same time,new branches sprout and fruits ripen from early May to late June.They shed their leaves in late October.Among them,Hongmanao has the earliest germination and Taiwan Changguo has the latest germination,four days later than Heizhenzhu.Taiwan Changguo also has the shortest growth period.（2）The mulberry varieties have different growth performance.Shensang,Baizhu,Taiwan Changguo and Jiuqulongsang have larger leaf length and width than the other four varieties.Shensang,Baizhenzhu and Hongmanao have higher ground diameters than the other varieties,while Dashi has the lowest.Baizhenzhu has the highest plant height and Hongguo No.3 has the lowest.Shensang and Taiwan Changguo have the highest leaf shape index,whereas Jiuqulong has the lowest.Shensang has the widest crown and Hongmanao has the narrowest,which affects the photosynthetic absorption of trees.Baizhenzhu,Taiwan Changguo and Shensang differ significantly from the other five fruit mulberry varieties in ground diameter,plant height and crown width.（3）The leaf nutritional quality varies greatly among mulberry varieties.Heizhenzhu has the highest crude fiber content,followed by Hongmanao,while Hongguo No.3 has the lowest.Hongmanao has the highest crude fat content,followed by Heizhenzhu,whereas Jiuqu Longsang has the lowest.Dashi has the highest coarse ash content,followed by Heizhenzhu,while Taiwan Changguo has the lowest fruit growth.Heizhenzhu has a high crude protein content,followed by Jiuqu Longsang,whereas Taiwan Changguo has the lowest fruit growth.The crude protein and coarse ash content differ significantly among varieties,but the crude fat and crude fiber content do not.（4）The mulberry varieties have different photosynthetic characteristics.The daily average net photosynthetic rate of the eight mulberry varieties exhibited a double-peak curve,with an evident“photosynthetic lunch break”and the first peak at13:00 am.Hongmanao had the highest net photosynthetic rate and Jiuqu Longsang had the lowest.The stomatal conductance followed a similar trend as the net photosynthetic rate.The intercellular CO₂concentration displayed a V-shaped curve with high values in the morning and evening and low values at noon.Shensang had the highest transpiration rate and Heizhenzhu had the lowest.The chlorophyll a/b values of the eight mulberry varieties in six months indicated that Shensang had the highest negative tolerance and Jiuqu Longsang had the lowest（Shensang>Heizhenzhu>Hongguo No.3>Taiwan Changguo>Hongmanao>Dashi>Baizhenzhu>Jiuqu Longsang）.Chlorophyll fluorescence Fv/Fm and NPQt values decreased to varying degrees,while q L values increased to varying degrees.In conclusion,the growth characteristics of the eight fruiting mulberry varieties vary.Hongmanao has small leaves with a low leaf shape index and a high stomatal conductance.Leaf size influences the crude protein and crude ash content of fruit mulberry.Shensang has high net photosynthetic rate,transpiration rate and intercellular CO₂concentration,while Jiuqu Longsang has the lowest net photosynthetic rate and stomatal conductance.However,Shensang leaves have a strong photosynthetic capacity.The comprehensive evaluation using the affiliation function method identified that Hongmanao,Dashi,Shensang and Baizhenzhu were suitable for introduction in Yulin area.We recommend that Shensang,Baizhenzhu,Hongmanao and Dashi be planted as dual-purpose varieties of fruit and leaves because of their strong adaptability in Yulin area.Heizhenzhu has a weak growth potential,but it can be planted as a fruit-producing variety.Taiwan Changguo,Hongguo No.3 and Jiuqu Longsang have vigorous growth and large leaves,which make them suitable for leaf-producing and ornamental purposes.