The Indian lac insect (Kerria lacca), a hemipteran, phloem sap sucking sedentary insect is an important bioresource which thrives on tender twigs of more than 400 plant species belonging to various genera and families. The most common commercial host plants for lac cultivation are big trees hence cultivation was concentrated mainly to dense forests across the country till last decade. Recently, a new bushy host plant belonging to the genus Flemingia has been introduced so that lac can be cultivated on farmlands like other cash crops. The insect is sedentary and feeds on the phloem sap of the host plants, the only source of its nutrition. Interestingly, the biological attributes of the insect as well as the qualitative and quantitative production of lac is influenced by the host plant on which the insect feeds upon. The present study was thus aimed at deciphering the effect of phloem sap constituents obtained from four plant host taxa belonging to the same genus Flemingia viz. F. semialata, F. macrophylla, F. bracteata and F. chapar (essential amino acids only-EAAs) on lac productivity. Moreover, a newer method for phloem sap collection i.e. Dot-blot in addition to the facilitated exudation using EDTA was also investigated. Dot-blot method for phloem sap collection also came out to be a promising method for field studies; although slightly higher concentration of EAAs were obtained from EDTA method, thus the later was used for further analysis. Phloem sap of four plant host taxa belonging to the same genus Flemingia were qualitatively and quantitatively analysed for seven EAAs (Arginine, Glycine, Leucine, Methionine, Phenylalanine Tyrosine and Valine). Amino acid concentration regime and further analysis done using statistical tools (ANOVA and PCA) points out the EAA concentration in the phloem sap is in congruency with the lac production data obtained through previous studies as F. semialata > F. macrophylla > F. chapar > F. bracteata. The present study thus scientifically points out that F. semialata can be a promising plant for lac cultivation on the basis of higher EAA content as compared to the rest three.

中文翻译：

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属于 Flemingia 属的四种 lac 宿主的必需氨基酸分析：其对 lac 生产力的影响。

印度紫胶昆虫 ( Kerria lacca），一种半翅目，吸吮韧皮部汁液的久坐昆虫是一种重要的生物资源，它在属于不同属和科的 400 多种植物的嫩枝上茁壮成长。紫胶栽培最常见的商业寄主植物是大树，因此直到过去十年，全国各地的栽培主要集中在茂密的森林中。最近，引入了一种属于 Flemingia 属的新的浓密寄主植物，以便紫胶可以像其他经济作物一样在农田上种植。这种昆虫是久坐不动的，以寄主植物的韧皮部汁液为食，这是其营养的唯一来源。有趣的是，昆虫的生物学特性以及 lac 的定性和定量生产受到昆虫赖以生存的寄主植物的影响。Flemingia即。F. semialata、F. macrophylla、F. bracteata和F. chapar（仅限必需氨基酸 - EAA）对紫胶生产力的影响。此外，除了使用 EDTA 促进渗出外，还研究了一种更新的韧皮部汁液收集方法，即斑点印迹法。韧皮部汁液收集的斑点印迹法也被证明是一种有前景的田间研究方法；尽管从 EDTA 方法获得了略高浓度的 EAA，因此后者用于进一步分析。同属Flemingia的四种植物寄主类群的韧皮部汁液对七种 EAA（精氨酸、甘氨酸、亮氨酸、蛋氨酸、苯丙氨酸、酪氨酸和缬氨酸）进行了定性和定量分析。氨基酸浓度方案和使用统计工具（ANOVA 和 PCA）进行的进一步分析指出韧皮部汁液中的 EAA 浓度与通过先前研究获得的 lac 生产数据一致，如F. semialata  >  F. macrophylla  >  F. chapar  >  F. 苞片。因此，本研究科学地指出F. semialata与其他三种植物相比，EAA 含量更高，因此是一种很有前途的紫胶栽培植物。