Research On Shade Tolerance Of Germplasm Resources Of Different Genotypes Of Spring Camelina Sativa(L.) Crantz

Camelina sativa(L.)Crantz,as a new source of food and feed,as well as a potential raw material for biofuel and biological products,is attracting much attention from researchers.Previous studies have shown the planting and production potential of Camelina sativa in intercropping systems.However,no shade tolerance genotypes of Camelina sativa have been developed or evaluated for shade tolerance of existing Camelina sativa genotypes.In this study,16 kinds of camelina sativa were evaluated for shade tolerance by pot experiment.Non-shade treatment(100%full light),low shade treatment(15%natural light intensity reduction),medium shade treatment(25%natural light intensity reduction)and high shade treatment(50%natural light intensity reduction)were applied to Camelina sativa seedlings(BBCH 103;Plants with 4-5 leaves)began shading treatment,and the tests were conducted in September 2020 and September 2021.The indices of photosynthesis(total chlorophyll,chlorophyll a,chlorophyll b,chlorophyll a/b and Fv/Fm),morphological traits(plant height,leaf area,number of branch plant-1,number of silicles plant-1),seed yield(seed yield plant-1,oil content and fatty acid composition(contents of each fatty acid,contents of fatty acid group and proportion of fatty acid)of each genotype were analyzed.The results are as follows:1.Different years,shading levels and genotypes significantly(P<0.05)affected chlorophyll content(total chlorophyll,chlorophyll a and chlorophyll b),chlorophyll fluorescence parameters Fv/Fm,chlorophyll a/b,leaf area,number of branch plant-1,number of silicles plant-1 and seed yield plant-1 of Camelina sativa.2.The chlorophyll content(total chlorophyll,chlorophyll a and chlorophyll b)and plant height of Camelina sativa were significantly(P<0.05)increased under shade treatment,while chlorophyll fluorescence parameters Fv/Fm,chlorophyll a/b,leaf area,number of branch plant-1,number of silicles plant-1 and seed yield plant-1 decreased significantly(P<0.05).Under shade treatment,total chlorophyll,chlorophyll a,chlorophyll b,chlorophyll a/b,plant height,leaf area,number of branch plant-1,number of silicles plant-1 and seed yield plant-1 of 16 different genotypes of Camelina sativa were different.In the experiment from 2020 to 2021,the total chlorophyll content of most of the genotypes,such as CamK7,CamK8,CamK9,CamC3 and CamC4,showed an increasing trend with the increase of shading level;Chlorophyll a/b of most genotypes,such as CamK1,CamK2,CamK3,CamK6 and CamK11 decreased with the increase of shading level;The plant height of each genotype showed an increasing trend with the increase of shade level.In the experiment from 2021 to 2022,the total chlorophyll content of most of the genotypes,such as CamK2,CamK3,CamK4,CamK5 and CamK6 genotypes showed an increasing trend with the increase of shading level;Chlorophyll a/b of most of the genotypes,such as CamKl,CamK2,CamK3,CamK4 and CamK9 showed a decreasing trend with the increase of shading level;Plant height of most genotypes,such as CamK1,CamK2,CamK3,CamK5 and CamK6,showed an increasing trend with the increase of shade level.3.With the increase of shade,the flowering time and flowering time of Camelina sativa under shade treatment were significantly(P<0.05)delayed and shortened,respectively.44.Different shading levels and genotypes significantly(P<0.05)affected the oil content,saturated fatty acid,monounsaturated fatty acid,polyunsaturated fatty acid and fatty acid ratio of camelina seed.Medium shade treatment and high shade treatment significantly(P<0.05)reduced seed oil content and unsaturated fatty acid content(monounsaturated fatty acid and polyunsaturated fatty acid).High shade treatment significantly(P<0.05)increased the content of saturated fatty acids in seeds.5.CamK9,CamC4 and ’SO-40’ were relatively shade tolerant genotypes among 16 Camelina sativa genotypes,according to the tree map constructed by comprehensive tolerance membership function values.These camelina genotypes were able to grow normally with natural light intensity reduced to 25%without affecting seed and oil yield,and showed high yield and tolerance,suggesting that CamK9,CamC4,and ’SO-40’ could be potential germplasm resources for intercropping with maize or other small food crops.