Effect Of Simulated Transportation On Postharvest Physiology And Cultivation Of Different Packagings A.konjac Seedlings

Amorphophallus konjac is the general term for the perennial herb of the Amorphophallus Blume of Araceae,it is the only important economic crop that has been discovered so far that can synthesize glucomannan in large quantities,and glucomannan is the best quality dietary fiber found today,and has a variety of special physical and chemical properties,making it widely used in food,medical,chemical and other fields.A.konjac is the most important cultivar in China,accounting for more than 90%of the cultivated area of Chinese A.konjac.The A.konjac has strong adaptability and wide range of fitness,it can adapt to the mountainous areas of all suitable A.konjac in China,especially the latitude north,high altitude,low temperature,weak sunshine and high humidity.With the continuous development of the value of A.konjac,the market demand has increased year by year,and the planting area has been expanding.Planting A.konjac has become one of the effective ways for poor mountain farmers to get rid of poverty and revitalize the local economy.the lack of A.konjac seedlings in the new district severely limits the development of the crop industry,so allocating seeds has become an important part of the development of the A.konjac.Years of results have shown that simple and extensive packaging and transportation will cause severe mechanical damage to the A.konjac seedlings,resulting in the prevalence of A.konjac soft rot,leading to a sharp drop in production.In this paper,the large amount of rot and the serious morbidity caused by the allocating seeds process of the A.konjac were studied,through the comparison of the characteristics of the A.konjac and other rood tuber,the key factors affecting the sensitivity of the A.konjac mechanical damage were found.Comparing and analyzing the damage of A.konjac seedlings and the incidence rate after planting in different periods and different packaging methods,the aim is to provide reference for the later A.konjac allocating seeds work and related research.The main findings are as follows:1 Study on sensitive factors of mechanical damage of rood tuberThe experiment used A.konjac,A.albus,A.bulbifer,A.krausei,A.paeoniifolius,potato,sweet potato,taro as the material,the differences in mechanical damage sensitivity of each test material were analyzed by comparing the impact resistance,water content,hardness and observating epidermal cell morphology of each test material.The results showed that the A.konjac,A.albus,A.bulbifer,A.krausei had obvious rot after impact damage,while A.paeoniifolius,potato,sweet potato,taro had no morbidity characteristics,indicating the first four specimens are more sensitive to mechanical damage than the latter.In the determination of water content,the water content of the A.konjac,A.albus,A.bulbifer,A.krausei were higher than 80%,the water content of the A.paeoniifolius,potato,sweet potato and taro were less than 80%,indicating that the water content was positively correlated with the sensitivity of mechanical damage.In the hardness measurement,the hardness of the A.konjac,A.albus,A.bulbifer,A.krausei was significantly lower than A.paeoniifolius,potato,sweet potato,taro,indicating that the smaller the hardness,the stronger the mechanical damage sensitivity.The electron microscopic observation of the epidermal cells could be obtained,the cell walls of the A.konjac,A.albus,A.bulbifer were thin,easy to rupture,the cells were arranged irregularly;the cell walls of the A.krausei,A.paeoniifolius and taro slack and thick,but relatively dense cells arranged irregularly;sweet potato and potato cell walls smooth firm,strong supportive.In summary,water content,hardness and epidermal cell morphology were important factors affecting the susceptibility of rood tuber seedlings to mechanical damage.The high water content,low hardness,epidermal cell wall was thin and bulky of A.konjac were the key to mechanical damage factor.2 Effects of mechanical damage on antioxidant enzyme activities of A.konjac bulbs during storageThe annual A.konjac bulbs were used as test materials,which were treated with 1mesh bag,2 plastic baskets,3 plastic baskets of Sawdust and 4 foam net bags.The A.konjac bulbs were packed in four different packaging methods,the simulated transport was carried out for 3 hours under at 180r/min,to determine the changes of antioxidant enzyme activities during the storage of different packaging A.konjac bulbs.The results showed that the POD,SOD,PPO,PAL activity and MDA content in the A.konjac bulbs of each treatment group were higher than those in the control A.konjac bulbs.The order of enzyme activity change from high to low was:treatment 1>treatment 2>treatment 3>treatment 4>control,treatment 4 and treatment 3 enzyme activity changes were close to the control,that was,the more serious the mechanical damage,the more antioxidant enzyme activity high.In summary,good packaging could significantly reduce the damage degree of A.konjac bulbs,which was more conducive to the transfer and allocating seeds of A.konjac.3 Effects of mechanical damage on changes in hormone content of A.konjac bulbs during storageThe contents of the hormones ABA,GA₃,ZR and IAA of A.konjac bulbs were measured by vibrating the simulated transport machinery.The results showed that the vibration treatment had a great influence on the ABA content,at the initial stage of treatment,the content of ABA in the treatment of A.konjac was increased rapidly,which was significantly higher than that of the control.With the prolongation of storage period,the content of ABA in the treatment 1 of A.konjac bulbs was significantly lower than other treatments and controls,it showed that the same treatment had the greatest impact on treatment 1.Mechanical damage had similar effects on the change trend of GA₃ and ZR content,and both showde a trend of stable growth in the early stage and rapid growth in the later stage;The effect of IAA content was small,and the difference between treatment group and control was not obvious.The trend of IAA was similar to that of ZR and GA₃,indicating that IAA synergized with ZR and GA₃.In the later stage of storage,the greater the mechanical damage,the lower the ABA content,the higher the content of GA₃,ZR and IAA,indicating that the mechanical damage was beneficial to the release of dormancy to some extent.4 Effects of mechanical damage on the decay of konjac bulbs during storageThe A.konjac bulbs packaged in four different ways were transported for 3 hours under at 180r/min in December,January,February,March and April.they were stored in plastic greenhouses after treatment,the rate of decay during the entire storage period was counted before sowing.The results showed that the incidence of A.konjac in different periods and different packaging simulation transports was significantly different during the whole storage period.In the same period of different packaging treatment,treatment 1 and treatment 2 A.konjac rot rate was significantly higher than treatment 3 and treatment 4,indicating that good packaging could effectively reduce the degree of injury of the mites.The rate of decay in December was the highest in the same packaging treatment of A.konjac rot in different periods.In December,the incidence of A.konjac was 12%,while in January,February,March,and April,the incidence was 9%,7%,5%,and 3%.The fresh A.konjac bulbs had high water content and were more sensitive to mechanical damage,so it was not advisable to carry out the allocating seeds and transportation when just harvesting.5 Effects of mechanical damage on the growth and pathogenesis of konjac plantsThe A.konjac bulbs were treated in different periods and in different packaging simulations were planted in the following year,and the incidence of the plants during the growth period was counted and the agronomic traits of the different treated plants were measured.The results showed that the incidence rates of treatment 1,treatment 2,treatment 3,and treatment 4 of different packaging treatments in December were 29%,20%,18%,and 12%,respectively,and treatments 1 and 2 were significantly higher than treatments 3 and 4,respectively,other groups also got the same result.From the growth of plants after planting,it could be concluded that the plant height and petiole length of the treated plants 1 and 2 were significantly higher than those of treatment 3and treatment 4 in December and January,and the emergence rate was earlier,indicating the mechanical vibration played a better role in promoting the dormancy of treatment 1 and treatment 2,while the promotion effect on treatment 3 and treatment 4was not obvious.Early release of dormancy caused the growth cycle of A.konjac to prolong,plant growth was high,but treatment 1 and treatment 2 soft rot were also higher,and the determination of petiole diameter,leaf disc diameter,length and width of the top cracked leaves of A.konjac showed overall growth of treatment 3 and treatment 4 was superior to treatment 1 and treatment 2.It showed that the packaging and transportation methods of treatment 3 and treatment 4 could effectively reduce the damage of A.konjac seedings and facilitate the healthy growth of plants.