Screening Of Cucumber Fruit Variation Mutant

Cucumber（Cucumis sativus L.,2n=2x=14）is one of the top ten vegetables in the world,and it is also the main vegetable crop cultivated in China.Cucumber cultivation area of China was 1.23 million hectares,with an annual output of 64.875million tons,accounting for 54.4%and 77.5%of the world’s total in 2017.The edible portion of the cucumber is the tender fruit,fruit traits are important agronomic characters,which directly affects economic benefits.Using EMS mutagenesis technology to create new germplasm,construct a cucumber mutant library and screen fruit mutants to provide excellent materials for fruit development mechanism research and cucumber breeding.The phenotype identification and data investigation of commercial melons and mature melons were carried out by using the M₂ generation,which had two generations of selfing and constructed cucumber inbred’6457’mutant library in the past.The main results are as follows:1.Under the conditions of cultivation in the greenhouse.The M₂ generation was as material to construct the M₃ generation population with 176 mutant lines through one self-pollination,and 44 typical lines with variation of fruit traits were screened out,which formed M₄ generation population.2.Under the greenhouse cultivation conditions,M₄ constructed by 528 strains of cucumber fruit mutant were used as materials and wild type’6457’as the control.Fruit traits were identified at the fruiting stage.（1）The melon has one kinds of fruit stalk shape variation（slippery shape）,two kinds of fruit color variation（white green,green）,three kinds of spine and warts density（no spine,thin spine,dense spine）,one kinds of spine（soft spine）and three kinds of warts variation（no warts,small warts,large warts）,there are 13 kinds of typical fruit variations;（2）There are 26homozygous lines,accounting for 59.1%.Filter out 1 small short cylindrical materials lines,1 spindle fruits lines,2 non-thinning materials lines,1 soft burr material line and other specific new germplasm;（3）The average fruit length of the wild type is23.0 cm,and the distribution of mutant cucumbers is 7.5²5.7 cm.Among them,the mutant m18s55 has the shortest length（9.0 cm）,which is only 39.1%of the length of the wild type fruit;（4）The average fruit diameter of the wild type is 3.0 cm,and the diameter distribution of the mutant fruit is 1.8⁴.3 cm.The mutant m18s55 has the largest diameter（5.1 cm）,1.7 times the wild type,and the mutant m18s9 has the smallest diameter of the fruit（1.8 cm）,which is 35.3%of the transverse diameter of m18s55.3.Data were investigated and analyzed for ripe melon fruit length,fruit diameter,fruit flesh thickness,fruit stalk length and fruit neck.Filter out 2 fruit lengthening material lines,5 fruit shortening material lines,1 fruit diameter larger material line,5fruit diameter smaller material lines,3 fruit flesh thickening material lines,and 14fruit stalk length material lines,1 fruit neck becomes a long material line,and 1 fruit neck becomes a short material line.（1）The average fruit length of the wild type is29.2 cm,and the mutant fruit length distribution is 10.0³8.1 cm.Among them,the mutant m18s18 has the longest fruit length（35.5 cm）,and the mutant m18s55 has the shortest length（10.0 cm）,which is only one in five of the longest melon;（2）The average fruit diameter of the wild type is 5.3 cm,and the distribution of the mutant cucumber is 4.0⁷.5 cm.The mutant m18s56 had the largest diameter（7.3 cm）and the mutant m18s55 has the smallest diameter（4.0 cm）;（3）The average fruit flesh thickness of the wild type is 0.9 cm,and the distribution of mutant cucumbers is0.5¹.5 cm,the mutant m18s55 has the smallest fruit flesh thickness（0.5 cm）.（4）The average fruit stalk length of the wild type is 4.4 cm.and the distribution of mutant cucumbers is 2.0⁵.3 cm.Among them,the mutant m18s61 melon had the longest stalk length（6.0 cm）,1.4 times of the wild type,the mutant m18s22 and m18s55haven’t fruit stalk;The average fruit stalk length of the wild type is 3.0 cm.and the distribution of mutant cucumbers is 2.7⁵.7 cm.Among them,the mutant m18s36melon has the smallest fruit stalk length（2.6 cm）.（5）The average fruit neck of the wild type is 3.0 cm,and the neck length distribution of the stalk of the mutant library is 0.8⁴.5 cm.Among them,the mutant m18s39 had the longest neck length（3.9 cm）,1.3 times that of the wild type,and the mutant m18s55 has the shortest neck length（0.8 cm）,which was only one fifth of the longest mutant of the fruit neck.