The Effects Of Exogenous Hormone Treatment On Walnut Fruit And Oil Components

Walnut belongs to Juglans genus of Juglandaceae,which is one of the four largest nuts in the world.The oil content of walnut kernel is generally 50%-70%,and its unsaturated fatty acid content is as high as 90%.In addition,walnut is rich in vitamins,calcium,iron,phosphorus,zinc and other nutrients which are very beneficial to human health.In 2019,the planting area of walnut in china has exceeded 100 million mu and the annual output has reached 3.627 million tons,which leads to the demand of fresh walnut has become saturated.At the same time,due to the decreasing economic benefits and the low yield and quality of walnut forest in some areas,the walnut forest in some areas has been abandoned or felled.Therefore,to develop the oil value of walnut and to improve its economic added value is an important measure to crack the excess production of walnut in china.At the same time,it is also of great significance to promote the sustainable and healthy development of walnut industry,increase farmers’ income and ensure the safety of edible oil in China.Based on this,the effects of exogenous hormone 6-BA,salicylic acid and paclobutrazol on the oil synthesis of walnut kernel were studied,and then the exogenous hormone treatment methods which can improve the oil yield or quality of walnut kernel were screened.The main results are as follows:(1)The effects of 6-BA on dry weight of walnut fruit were as follows:In the early stage,the weight of walnut dry fruit increased,but it was inhibited in the later stage.The effect of 6-BA on oil content of walnut kernel was:decrease-increasedecrease-slightly increases.The effects of 6-BA on the relative content of fatty acids in walnut kernel was as follows:The relative content of palmitic acid is decreaseincrease-decrease-increase.The change rule of relative content of stearic acid is decrease-unchanges-decrease-increase.The change rule of oleic acid content is constant-increase-decrease-increase-decrease.The relative content of linoleic acid is increase-decrease-increase.The relative content of linolenic acid is decrease-increase-decrease-increase.The relative content of saturated fatty acids is decreaseincrease.The change rule of relative content of unsaturated fatty acids is increasedecrease-increase-decrease-increase.The relative content of polyunsaturated fatty acids is increase-unchange-decrease-unchange.6-BA treatment of walnut fruit inhibit the transformation of linoleic acid to linolenic acid on the first day,promote the transformation of linoleic acid to linolenic acid on the seventh day,promote the transformation of oleic acid to linoleic acid on the fourteenth day,promote the transformation of stearic acid to oleic acid on the 28th day,inhibit the transformation of linoleic acid to linolenic acid,and promote the transformation of oleic acid to linolenic acid during walnut ripening The process of acid conversion.(2)Effect of salicylic acid on Walnut dry fruit weight:the increase of dry fruit weight was inhibited as a whole.Salicylic acid inhibited walnut kernel growth at later stage.The effect of salicylic acid on oil content of walnut kernel is:decreaseincrease.The effects of salicylic acid on fatty acid composition of walnut kernel were as follows:The relative content of palmitic acid is decrease-increase-decrease-increase-slightly decrease.The relative content of stearic acid decrease-unchangesincrease.The relative content of oleic acid is decrease t-increase.The relative content of linoleic acid is increase-decrease.The relative content of linolenic acid is increase-decrease.The change rule of relative content of saturated fatty acids is decreaseincrease.The change rule of relative content of unsaturated fatty acids is decreaseincrease-decrease-slightly increase.The change rule of relative content of polyunsaturated fatty acids is increase-unchanges-decrease.Salicylic acid inhibite the conversion of saturated fatty acids on the first day,promote the conversion of oleic acid to linoleic acid on the seventh day,promoted the conversion of linoleic acid to linolenic acid on the fourteenth day,promote the conversion of linoleic acid to linolenic acid on the 28th day,and inhibite the conversion of oleic acid to linoleic acid during walnut ripening.(3)The effects of paclobutrazol on dry fruit weight and kernel weight of walnut were as follows:The dry fruit increased first and then decreased,and the kernel weight process increased later.The effect of paclobutrazol on the oil content of walnut kernel:increase.The effects of paclobutrazol on the relative content of fatty acids in walnut kernel were as follows:The relative content of palmitic acid is increasedecrease-increase-decrease-increase.The relative content of stearic acid is increase.The relative content of oleic acid relative content is decrease-increase.The relative content of linoleic acid changed is:increase-decrease-increasedecrease.The relative content of linolenic acid is increase-decrease-increase.The relative content of saturated fatty acids is increase-decrease-increase-unchangesincrease.The change rule of relative content of unsaturated fatty acids is increase-decrease-increase-decrease.The relative content of polyunsaturated fatty acids is increase-decrease.Paclobutrazol promote the conversion of oleic acid to linoleic acid on the first day,promote the conversion of oleic acid to linoleic acid on the seventh day,inhibited the conversion of oleic acid to linoleic acid on the fourteenth day,inhibite the conversion of linoleic acid to linolenic acid on the 28th day,and promote the conversion of oleic acid to linoleic acid during walnut ripening.6-BA had little effect on the oil content of walnut kernel,but which could increase the relative content of linoleic acid and unsaturated fatty acid,and reduce the relative content of oleic acid.Salicylic acid can increase the content of oleic acid,but which reduce the content of linoleic acid,linolenic acid and polyunsaturated fatty acid.Paclobutrazol could increase the oil content and oleic acid content of walnut,and which reduce the contents of linoleic acid,unsaturated fatty acid and para unsaturated fatty acid.