| Lilium.Lancifolium is a perennial herbaceous plant belonging to the genus Lilium.Its bulbs are rich in starch,polysaccharide,protein,pectin,vitamins and so on.Lilium.Lancifolium is a medicinal lily in"《Chinese Pharmacopoeia》"It has the effects of moistening lung and relieving cough,clearing heart and tranquilizing mind.It is used for Yin deficiency and dry cough,deficiency and palpitation,insomnia and dreams.In order to improve the yield and quality of medicinal and edible Chinese herbal medicine Lindera,the effects of different potassium fertilizer rates on photosynthesis and main effective components of Lindera were studied to provide theoretical basis for production practice.A total of seven K fertilizer treatments:Kl(0kg·hm-2)、K2(50kg·hm-2)、K3(100kg·hm-2)、K4(150kg·hm-2)、K5(200kg·hm-2)、K6(250kg·hm-2)、K7(300kg·hm-2),were set to study the effects of K fertilizer application rates at seedling stage（04.07）,vigorous growth stage（05.07）,bud stage（05.28）,bulb expansion stage（06.30）,and harvest stage（08.10）on the growth characteristics,photosynthetic physiological indexes,antioxidant enzymes,yield,active ingredient content,and K absorption and utilization of Lilium.Lancifolium,the effects of K fertilizer application rates on photosynthetic physiology and yield of Lilium.Lancifolium The results are as follows:1.Effects of potassium fertilizer application rate on morphological characteristics and biomass of Lilium.Lancifolium.Suitable amount of potassium fertilizer can promote the growth of plant height,stem diameter and leaf number.When the amount of potassium fertilizer in K1～K4(0～150 kg·hm-2),and in K4 treatment reached the maximum,respectively 40,63,76.When the amount of potassium fertilizer>K4(150 kg·hm-2),the number of leaves decreased with the increase of potassium fertilizer.The plant height at seedling and bud stages reached the maximum values of 28 cm and 69.5 cm under K5(200 kg·hm-2)treatment.In the vigorous growth period,K4(150 kg·hm-2)treatment reached the maximum 56 cm.The stem diameter of Lilium.Lancifolium.decreased with the growth process.The maximum stem diameter under K5(200 kg·hm-2)treatment at different growth stages was 9.24 cm,8.91 cm and 8.37 cm,respectively.Subsequently,the stem diameter gradually decreased with the increase of K application rate.There was a significant positive correlation between leaf number and potassium application rate.Plant height,stem diameter,leaf number and potassium fertilizer rate were significantly positively correlated.There was no significant correlation between plant height and potassium application rate at bud stage,while leaf number and stem diameter were significantly positively correlated with potassium application rate.The suitable amount of potassium fertilizer increased the dry matter weight of L.japonica.When the amount of potassium fertilizer was K5(200 kg·hm-2),the dry matter weight of Lilium.Lancifolium at different growth stages were 1.22 g,1.89 g,8.29 g and 12.43 g,respectively.There were significant differences in stem dry matter among different potassium fertilizer treatments at seedling stage,vigorous growth stage and Significant difference（p<0.05）,but no significant difference in bud stage（p>0.05）.There were significant differences in leaf and bulb dry weight at different stages.2.Effect of Potassium Fertilizer Rate on Photosynthetic Characteristics of Lilium.Lancifolium.1)Appropriate amount of potassium fertilizer to promote the pn.With the increase of potassium fertilizer application rate,Pn of leaf showed ’high-low’change.2)The diurnal variation of net photosynthetic rate（Pn）showed a bimodal curve at different growth stages,and reached the highest value at 10:00.Intercellular CO2 concentration（Ci）decreased with the increase of ambient light intensity and temperature,reaching the valley value at 13:00.The change trend of stomatal conductance（Gs）was the same as that of pn.The transpiration rate（Tr）first increased and then decreased with the increase of ambient temperature,reaching the highest level at 15:00.3)There was no significant difference in chlorophyll content（Chl）among treatments at seedling stage.Chl at vigorous growth stage and bud stage was significantly positively correlated with K application rate,reaching the highest value at K5(200 kg·hm-2).4)The expression of RLS and RSS was inhibited by insufficient potassium fertilizer and excessive potassium fertilizer.RSS expression reached the highest value at K4(150 kg·hm-2).RLS expression was highest in K5(200kg·hm-2).The expression levels of RSS and RLS were the lowest at K7(300 kg·hm-2).Rubisco activity（RuBP）and photochemical electron efficiency（Fv/Fm）were highest at K5(200kg·hm-2).Rubisco activity is the main factor affecting net photosynthetic rate.3.Effect of Potassium Fertilizer Application Rate on Antioxidant Enzyme Content of Lilium.Lancifolium.On the whole,the SOD activity showed a "high-low-high " change with the amount of potassium fertilizer,and the activity was the lowest at K5(200 kg·hm-2).The change trend of CAT activity was similar to SOD,and the activity was the lowest at K5(200 kg·hm-2).POD activity was not significantly different in leaves.K4(150kg·hm-2)showed the lowest activity in bulb.SOD,CAT and POD increased when K fertilizer application was too high or too low.4.Effect of Potassium Fertilizer Application on the Content of Active Components in Lindera.The content of total flavonoids in bulbs of Lilium.Lancifolium increased first and then decreased with the increase of K application rate at harvest stage.When the K application rate was K2(50kg·hm-2),the content of total flavonoids reached the maximum value of 2.57 mg·g-1.The lowest content of total flavonoids was 0.66 mg·g-1 at K6(250kg·hm-2).The polysaccharide content increased first and then decreased with the increase of K fertilizer application rate,and reached the maximum of 35.71 mg·g-1 at K5(200kg·hm-2).The lowest polysaccharide content was 13.40 mg·g-1 without K treatment.Saponin content showed a bimodal change with the increase of potassium fertilizer,and the highest saponin content reached 2.26 mg·g-1 when potassium fertilizer was K2(50kg·hm-2).The lowest was 1.19 mg·g-1 at K7(300kg·hm-2).5.Effect of Potassium Application Rate on Potassium Accumulation and Distribution in Lilium.Lancifolium.1)Appropriate amount of potassium fertilizer can promote the accumulation of potassium.With the increase of potassium fertilizer application rate,the change of potassium accumulation was not obvious.The potassium accumulation of stems,leaves and bulbs reached the maximum with the increase of potassium application rate at K5(200 kg·hm-2).There was a significant positive correlation between potassium absorption and yield.The control treatment had the highest potassium use efficiency.2)Potassium mainly accumulated in leaves and stems at seedling stage,leaves accounted for 54.5%of the total potassium accumulation,and stems accounted for 30.3%.The vigorous growth period gradually transferred to bulbs,and the potassium accumulation in bulbs increased to 28.8%.Potassium accumulation in leaves of Lilium.Lancifolium at bud stage still accounted for 43.8%,and potassium accumulation in bulbs reached 30.6%.Potassium mainly accumulated in bulbs at bulb expansion stage accounted for 52.3%of the total potassium accumulation.6.Effect of potassium fertilizer application on yield index of Lilium.Lancifolium.With the increase of potassium fertilizer application rate,the total yield of Lindera rose first and then decreased,and there was a significant positive correlation between potassium fertilizer application rate K1～K5(0～200 kg·hm-2).When the amount of potassium fertilizer was K5(200 kg·hm-2),the total yield reached the highest,15834.15 kg·hm-2.When the amount of potassium fertilizer was>K6(250 kg·hm-2),the total yield decreased with the increase of potassium fertilizer,and the yield ranged from 10889.1 kg·hm-2 to 15834.15 kg-hm-2.When the amount of potassium fertilizer was K5(200 kg·hm-2),the bulb diameter（9.14cm）,bulb height（5.64cm）,single leaf width（3.18cm）,bulb fresh weight（213.92g）and bulb dry weight（68.01 g）were the highest.When the amount of potassium fertilizer was K6(250 kg-hm-2),the maximum length of single leaf was 5.25cm.When the amount of potassium fertilizer was K3(100kg·hm-2),the maximum single leaf thickness was 4.02 mm.The highest number of bulb branches was 4.75 at K6(250 kg·hm-2). |
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