An investigation of long coleoptile wheat for WA farming systems

This trial was designed as a scoping study to investigate various aspects of long coleoptile wheat relative to WA farming systems for eventual grower integration. However, this report outlines both observations as well as extensive data that was collected and analysed, despite the original aim of the trail to be more investigatory than data-driven in nature.The main area of research was investigating the novel Rht18 gene in wheat, which allows for an elongated coleoptile: a protective sheath around the emerging shoot from a seed. Mace/Scepter typically have 40-60 mm coleoptiles (depending on environmental factors). New varieties developed by CSIRO with the Rht18 gene can extend to 12-140 mm by comparison.This 2-year project has assessed long coleoptile wheat applications to farming systems in WA across emergence, establishment, weed competition, rhizoctonia impacts, herbicide interactions and yield. Extension across sites has aided in discussions with growers and areas requiring further study for integration to grower systems. While investigatory in nature, 2022 trials outlined in this report aimed to be more data driven in nature than trials conducted in 2021.The two-year scoping study aimed to achieve the following objectives for investigate various aspects of long coleoptile wheat relative to WA farming systems for eventual grower integration:• Extend long coleoptile findings and discussions to growers across agricultural regions of Western Australia• Quantify differences in emergence from deep and shallow sown varieties with varying coleoptile lengths.• Investigate emergence through furrow fill from wind and rain events.• Investigate emergence from uneven soil platforms, such as from deep-ripping• Investigate emergence through both low and high soil temperatures.• Explore biomass and vigour differences between varieties with and without the Rht18 gene.• Quantify differences in annual ryegrass competition and wheat vigour interactions with grass weeds.• Explore herbicide interactions across depths of sowing to investigate crop safety and ways of adjusting/changing IBS and EPE herbicides.• Explore rhizoctonia wheat root infection between depths of sowing.• Analyse grain yield of various varieties and coleoptile lengths, including Rht18 wheat.

本试验作为一项范围界定研究（scoping study），旨在探究长胚芽鞘（coleoptile）小麦针对西澳大利亚州（Western Australia，简称WA）种植系统的诸多相关特性，以最终实现面向种植户的应用推广。不过，尽管本试验最初的设计初衷更偏向探索性而非数据驱动，但本报告不仅梳理了观测结果，还收录了经采集与分析的海量实验数据。

本研究的核心方向为探究小麦中的新型Rht18基因，该基因可使胚芽鞘伸长——胚芽鞘是包裹种子萌发幼芽的保护性鞘状结构。常规的Mace与Scepter品种胚芽鞘长度通常为40~60毫米（具体数值受环境因素影响），而由澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation，简称CSIRO）培育的携带Rht18基因的新品种，其胚芽鞘长度可达12~140毫米。

本为期两年的项目针对西澳大利亚州种植系统中的长胚芽鞘小麦应用展开了多维度评估，涵盖出苗、建苗、杂草竞争、丝核菌（Rhizoctonia）病害影响、除草剂互作以及籽粒产量等方面。多试验点的研究助力了与种植户的沟通交流，并明确了面向种植户系统应用时需进一步开展研究的方向。尽管本研究整体偏向探索性，但本报告中提及的2022年试验相较于2021年的试验，更偏向数据驱动的研究模式。

这项为期两年的范围界定研究旨在针对长胚芽鞘小麦适配西澳大利亚州种植系统以实现种植户应用的相关维度达成以下研究目标：
• 将长胚芽鞘小麦的研究成果与讨论内容推广至西澳大利亚州农业产区的种植户
• 量化不同胚芽鞘长度的品种在深播与浅播条件下的出苗差异
• 探究受风力与降雨影响形成的垄沟填充条件下的出苗情况
• 探究因深松作业形成的非平整土壤台面条件下的出苗表现
• 探究高低两种土壤温度环境下的出苗情况
• 对比分析携带与不携带Rht18基因的品种在生物量与生长活力上的差异
• 量化一年生黑麦草（annual ryegrass）竞争与小麦生长活力间的互作效应及其与禾本科杂草的相互作用
• 探究不同播种深度下的除草剂互作效应，以研究作物安全性以及调整或更换IBS与EPE除草剂的方法
• 探究不同播种深度下的小麦丝核菌根部侵染情况
• 分析不同品种与胚芽鞘长度（包括携带Rht18基因的小麦）的籽粒产量。