Format: ORAL

Jan Sher1,3*, Nasrullah Khan2, Kyle W. Tomlinson1

1.Center for Integrative Conservation & Yunnan Key Laboratory for Conservation of Tropical Rainforests and Asian Elephants, Xishuangbanna Tropical Botanical Garden, Mengla, Yunnan 666303, China 2.Department of Botany, University of Malakand Pakistan 3.University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 10049, China

Background: Plants have the ability to recognize their kin neighbours, which may be a beneficial trait that increase inclusive fitness, by suppressing individual growth to support the combined growth of the group. However, the advantages of kin cooperation (known as kin selection theory), may differ across environmental gradients, with competition between related individuals potentially being detrimental under resource limitation (following niche partitioning theory). Aims: The study aimed to understand how quinoa (Chenopodium quinoa (Willd) plants grow with kin or with non-kin under different nutrient supply rates. Methods: Plants were grown in treatments post-germination for 70 days. Biomass accumulation, allocation to organs, and organ traits related to resource acquisition were measured at the end of the experiment. Results: Total mass and shoot mass were greater for plants grown with kin than with non-kin across nutrient treatments. Plants grown with kin had greater root allocation than with non-kin under low and high nutrients. Allocation to leaves, specific leaf area, and average leaf mass were greater for plants grown with non-kin than kin under high nutrient supply, but did not differ under low nutrient supply. Allocation to stem was greater for plants grown with kin than non-kin under high nutrient supply, but did not differ under low nutrient supply. Specific taproot length and specific stem length were respectively positively and negatively related to increased fertility, but unrelated to kinship. Conclusions: Our results suggest that both niche partitioning and kin selection processes may be at play in quinoa, depending on whether soil nutrient competition is more important. Under both situations, quinoa plants always grew better with kin than non-kin regardless of soil nutrient conditions.