磷肥用量对马铃薯淀粉理化性质及产量的影响

Effects of phosphorus fertilizer application rates on physicochemical properties and yield of potato starch

【目的】研究不同磷肥用量对马铃薯淀粉理化性质及产量的影响,为不同用途马铃薯的磷肥科学管理提供参考。【方法】以早熟马铃薯‘尤金’和中晚熟马铃薯‘克新13号’为供试品种,在黑龙江省开展了两年田间试验。分别设置P_(2)O_(5)用量为0(CK)、45(低磷Low P,LP)、90(中磷Middle P,MP)和135(高磷High P,HP)kg/hm^(2)4个处理,测定了收获后马铃薯淀粉的部分理化性质、淀粉产量等指标。【结果】两年平均结果表明,与CK相比,增施磷肥可降低马铃薯直链淀粉含量,‘尤金’降幅为3.19%~5.14%,‘克新13号’降幅为2.97%~9.05%,其中HP处理与CK差异显著(P<0.05,2019年‘尤金’除外)。随着磷肥用量的增加,淀粉的透明度和膨胀度提高,溶解度降低。与CK相比,‘尤金’HP处理的淀粉透明度提高15.00%(P<0.05),膨胀度提高3.94%,溶解度降低12.23%(P<0.05);‘克新13号’HP处理的淀粉透明度提高25.74%(P<0.05),膨胀度提高7.90%(P<0.05),溶解度降低21.84%(P<0.05)。‘尤金’淀粉颗粒的中位径(D_(50))在MP处理最高,较CK增加11.58%(P<0.05);‘克新13号’淀粉颗粒的中位径(D_(50))随施磷量的增加而降低,HP处理较CK降低5.02%(P<0.05),但‘克新13号’的中位径明显高于‘尤金’。‘尤金’的MP处理淀粉产量较CK平均增加31.36%(P<0.05),‘克新13号’的HP处理淀粉产量较CK平均增加29.66%(P<0.05)。【结论】适量增施磷肥有助于提高马铃薯块茎的干物质含量及产量,从而提高马铃薯淀粉的产量。适量的磷肥还可降低马铃薯直链淀粉含量,增加支链淀粉含量,提高淀粉的透明度和膨胀度,提高淀粉的品质。在本研究条件下,综合磷对马铃薯淀粉理化性质和产量的影响,‘尤金’的P_(2)O_(5)适宜用量为90 kg/hm^(2),‘克新13号’的P_(2)O_(5)适宜用量为135 kg/hm^(2)。

【Objectives】This study investigated the effects of P application rates on the physicochemical properties and yield of potato starch used for different purposes.【Methods】Field experiment was conducted in Heilongjiang Province in 2019 and 2020,using‘Youjin’and‘Kexin 13’potato cultivars as test materials.The treatments were low(P_(2)O_(5)45 kg/hm^(2),LP),medium(P_(2)O_(5)90 kg/hm^(2),MP),and high(P_(2)O_(5)135 kg/hm^(2),HP)P application rate,with no P application designated as the control(CK).The physicochemical properties and yield of potato starch were determined.【Results】P application reduced the amylose content of potato starch by 3.19%−5.14%for‘Youjin’and 2.97%−9.05%for‘Kexin 13’compared to CK;the decrease in cultivar‘Youjin’in 2019 under HP was more pronounced than other treatments.The addition of P to potato starch increased its transparency and swelling capacity while decreasing its solubility.Compared with CK,HP(P<0.05)increased starch transparency by 15.00%(Youjin)and 25.74%(Kexin 13),increased swelling power by 3.94%(Youjin)and 7.90%(Kexin 13),and decreased solubility by 12.23%(Youjin)and 21.84%(Kexin 13).The median diameter(D_(50))of‘Youjin’was the highest under MP treatment(11.58%higher than CK),while‘Kexin 13’recorded a decrease in D_(50) with an increasing P application rate.The D_(50) of‘Kexin 13’in HP was 5.02%lower than CK.However,the D_(50) of‘Kexin 13’was larger than‘Youjin’.The starch yield of‘Youjin’under MP treatment and‘Kexin 13’under HP treatment was the highest,corresponding to 31.36%and 29.66%increase compared to CK.【Conclusions】Appropriate P fertilizer application rate efficiently increased the dry matter accumulation and starch yield of potato.Further,it can boost amylopectin levels and improve potato starch’s transparency and swelling power.The optimum application rate of P_(2)O_(5) is 90 kg/hm^(2) for‘Youjin’and 135 kg/hm^(2) for‘Kexin 13’.