Effects Of Several Dwarf Interstocks On Growth And Fruit Quality Of ’Ruiyang’ And ’Ruixue’ Apple In Longdong Area Of Gansu

Dwarfing and dense planting is the general trend in the development of modern apple cultivation,and is also the reform direction of apple cultivation mode in China.More than 80%of the existing dwarf cultivated orchards in China still adopt the dwarf interstock cultivation method.Longdong,Gansu,is an advantageous production area with the most development potential for high-quality apple production in my country.In order to promote high-quality and efficient production of apples in this area,it is very important to develop excellent varieties,select suitable rootstocks,and promote dwarf cultivation models.To this reason,based on the site conditions of the Longdong apple producing area,this study took the newly bred’Ruiyang’and’Ruixue’varieties as the objects at the Qingcheng Apple Experiment Station of Northwest A&F University in Gansu from 2020 to 2021.Five dwarf interstocks,including SH₆,SC₁,SH₃₈,M₂₆and M₉-T₃₃₇,were used as test materials.The growth performance and fruit quality-related indicators of two new varieties on different interstocks were measured and analyzed.The purpose is to provide technical basis for the selection of suitable dwarf interstocks for new varieties.After 2 years of research analysis,the main results are as follows:1.Combination effects of four interstocks(SH₆,SC₁,M₂₆ and M₉-T₃₃₇)and’Ruiyang’apple scion were studied.Studies on apple growth and fruiting characteristics of different rootstocks shows that the degree of dwarfing from strong to weak was SH₆>M₂₆>M₉-T₃₃₇>SC₁,among which SH₆ tree height was less than 320 cm,the tree vigor was weak.The flowering period of SH series was 2～3 days later than that of M series,and the flowering period was longer.The M₉-T₃₃₇ had the highest yield,followed by SC₁ and M₂₆,while SH₆ had the lowest yield,which was only 1/3 of M₉-T₃₃₇.Studies on fruit quality show that,SH series was better than M series in fruit coloring,the soluble solids content,soluble sugar content,and sweetness value.Among them,the soluble sugar content was above 120 mg·g^-1,and the sweetness value is above 150;M₂₆ had the highest esters(386.87μg·kg^-1)and olefins(11.34μg·kg^-1),and had a strong fragrance(26.8μg·kg^-1),followed by SH₆ and SC₁,and M₉-T₃₃₇ had higher aldehydes(29.82μg·kg^-1)and alcohols(11.77μg·kg^-1);The anthocyanin content,total phenolic content,total flavonoid content and Vc content of SH₆,SC₁ and M₂₆were higher than those of M₉-T₃₃₇.2.Combination effects of five interstocks(SH₆,SH₃₈,SC₁,M₂₆ and M₉-T₃₃₇)and’Ruixue’apple scion were studied.Studies on apple growth and fruiting characteristics of different rootstocks shows that the degree of dwarfing from strong to weak was SH₆>M₂₆>M₉-T₃₃₇>SC₁>SH₃₈,the flowering period of SH series was 2～3 days later than that of M series,and the flowering period was longer.SH₃₈ had the highest yield,followed by SC₁,M₂₆ and M₉-T₃₃₇,while SH₆ had the lowest yield,which was only 1/2 of SH₃₈.Studies on fruit quality show that,SH₆、SH₃₈和SC₁ was superior to M₂₆ and M₉-T₃₃₇ in fruit appearance,the soluble solids content,soluble sugar content,sweetness value,solid-acid ratio,sucrose content and glucose content,among which SH₆ and SC₁ were the most prominent,with a soluble sugar content of over 135 mg·g^-1 and the sweetness value was above 178.The content of aldehydes(70.84μg·kg^-1)is the highest in SC₁,followed by SH₃₈ and SC₁,the esters of SH₃₈(68.45μg·kg^-1)are higher,and SH₆ had higher olefins content.Total phenolic content,flavonoid content and Vc content were highest in SH₆,followed by SH₃₈,SC₁ and M₂₆.In summary,the comprehensive comparative analysis of growth characteristics,yield and fruit quality and other related indicators,The’Ruiyang’apples of SC₁ and M₂₆ performed well in the Longdong area of Gansu.the fruit flavor of M₉-T₃₃₇ was second,and the yield of SH₆ was low and the tree vigor was weak.Causes premature senescence of trees and poor adaptability in Longdong area.The’Ruixue’apple has the characteristics of short branches,and the semi-dwarf rootstock SC₁ and SH₃₈ have good comprehensive performance in Longdong area of Gansu;M₂₆ and M₉-T₃₃₇ have average fruit flavor,and the performance is second.SH₆ has poor high yield and poor adaptability in Longdong area.