印度喜马拉雅地区(IHR)的农业用地容易受到各种降雪的影响,会导致营养浸出,低温,和干旱条件。目前的研究,因此,寻求一种本土的嗜冷植物生长促进(PGP)细菌接种剂,具有在寒冷和干旱胁迫下减轻作物生产力的潜力。筛选了从喜马拉雅西北部拉哈德谷的夜间土壤堆肥中预先分离出的嗜冷细菌,以进行磷酸盐(P)和钾盐(K)的溶解,固氮,吲哚乙酸(IAA)生产,铁载体和HCN的产生)以及它们对干旱条件的耐受性,以促进聚生体发育。此外,在寒冷的半干旱条件(50%田间能力)下,通过盆栽实验评估了选定的财团对小麦(TriticumaestivumL.)和玉米(ZeamaysL.)生长发育的影响。在57种具有P和K增溶的细菌中,固氮,IAA生产,铁载体和HCN生产,假单胞菌蛋白原LPH60,假单胞菌LSH24,粪冷杆菌LUR13,沙雷氏菌变种LUR44,假单胞菌粘虫LUR70和谷氨酸杆菌LUR77表现出对干旱胁迫的耐受性(-0.73MPa)。这些耐旱性PGP菌株对小麦和玉米种子的定殖导致发芽指数>150,表明在干旱胁迫下没有植物毒性。值得注意的是,一种特殊的菌株,假单胞菌。LPH60对三种植物病原体Ustilagomaydis具有拮抗活性,尖孢镰刀菌,和镰刀菌。用财团处理显着增加了小麦和玉米植物的叶子(100%和160%)和根(200%和133%)生物量,分别。此外,LPH60和LUR13与密切相关菌株的全基因组序列比较揭示了与植物养分吸收相关的基因,植物激素合成,铁载体生产,氰化氢(HCN)合成,挥发性有机化合物的生产,海藻糖和甘氨酸甜菜碱运输,冷冲击反应,超氧化物歧化酶活性,以及非核糖体肽合成酶和聚酮合成酶的基因簇。凭借他们的PGP品质,生物防治活性,以及承受环境挑战的能力,已开发的财团代表了在寒冷的半干旱地区种植的谷物作物的一种有前途的冷和干旱活性PGP生物接种剂。
The agricultural land in the Indian Himalayan region (IHR) is susceptible to various spells of snowfall, which can cause nutrient leaching, low temperatures, and drought conditions. The current study, therefore, sought an indigenous psychrotrophic plant growth-promoting (PGP) bacterial inoculant with the potential to alleviate crop productivity under cold and drought stress. Psychrotrophic bacteria preisolated from the night-soil compost of the Lahaul Valley of northwestern Himalaya were screened for phosphate (P) and potash (K) solubilization, nitrogen fixation, indole acetic acid (IAA) production, siderophore and HCN production) in addition to their tolerance to drought conditions for consortia development. Furthermore, the effects of the selected consortium on the growth and development of wheat (Triticum aestivum L.) and maize (Zea mays L.) were assessed in pot experiments under cold semiarid conditions (50 % field capacity). Among 57 bacteria with P and K solubilization, nitrogen fixation, IAA production, siderophore and HCN production, Pseudomonas protegens LPH60, Pseudomonas atacamensis LSH24, Psychrobacter faecalis LUR13, Serratia proteamaculans LUR44, Pseudomonas mucidolens LUR70, and Glutamicibacter bergerei LUR77 exhibited tolerance to drought stress (-0.73 MPa). The colonization of wheat and maize seeds with these drought-tolerant PGP strains resulted in a germination index >150, indicating no phytotoxicity under drought stress. Remarkably, a particular strain, Pseudomonas sp. LPH60 demonstrated antagonistic activity against three phytopathogens Ustilago maydis, Fusarium oxysporum, and Fusarium graminearum. Treatment with the consortium significantly increased the foliage (100 % and 160 %) and root (200 % and 133 %) biomasses of the wheat and maize plants, respectively. Furthermore, whole-genome sequence comparisons of LPH60 and LUR13 with closely related strains revealed genes associated with plant nutrient uptake, phytohormone synthesis, siderophore production, hydrogen cyanide (HCN) synthesis, volatile organic compound production, trehalose and glycine betaine transport, cold shock response, superoxide dismutase activity, and gene clusters for nonribosomal peptide synthases and polyketide synthetases. With their PGP qualities, biocontrol activity, and ability to withstand environmental challenges, the developed consortium represents a promising cold- and drought-active PGP bioinoculant for cereal crops grown in cold semiarid regions.