南方低甲烷排放的高产水稻品种筛选与评价

Screening for and evaluation of rice (Oryza sativa) varieties with low methane emission and high yield in South China

为综合评价高产和低甲烷(CH4)排放兼具的水稻品种,应对我国粮食安全和环境保护问题,于2013年晚季和2014年早季,以南方稻区50个代表品种为供试材料,在盆栽条件下采用静态箱-气相色谱法测定品种的CH4排放通量,并对生育期的CH4排放量、稻谷产量及植株农艺性状进行了综合评价。结果表明,早、晚季供试品种间的CH4排放量和产量均存在显著差异。早季全生育期的CH4排放量在7.37～21.10 g·m-2之间,晚季分蘖期至幼穗分化期的CH4排放量在1.37～13.97 g·m-2之间;早季产量在0.40～0.65kg·m-2之间,晚季在0.59～0.87 kg·m-2之间。根据系统聚类法的分析结果,将供试品种划分成具有不同CH4排放量和产量水平的类型,从中筛选出了适合推广应用的CH4低排高产、中排高产和低排中产品种,如黄华占、五优308、丰华占、特三矮、茉莉占选、广超丝苗、珍桂矮、广恢998和七桂早25等。其中,恢复系广恢998组配品种、黄华占和五优308已在我国南方稻区大面积推广应用。相关分析结果表明,株高、叶面积指数与CH4排放通量呈显著正相关,这2个性状可作为高产低CH4排放水稻新品种选育的辅助筛选指标。此外,稻谷产量与CH4排放量无显著相关。研究结果为培育高产与低CH4排放兼具的新品种提供了亲本材料和理论依据。

Adopting rice varieties with high yield and low methane(CH4)emission is important for food security and environmental protection in China.However,the evaluation of such rice varieties with both high yield and low CH4emission has rarely been documented.In the late season of2013and early season of2014,pot experiments were carried out to evaluate the CH4emission,grain yield,and agronomic traits of50rice varieties widely grown in South China.The CH4fluxes of the rice varieties were determined via the static chamber/gas chromatograph technique.CH4emission and grain yield displayed significant differences among the varieties.The amount of CH4emission ranged between7.37and21.10g·m^-2throughout the growing period for the early-season rice and between1.37and13.97g·m^-2during the period from tillering to panicle differentiation for the late-season rice.The grain yield ranged between0.40and0.65kg·m^-2for the earlyseason rice and between0.59and0.87kg·m^-2for the late-season rice.According to cluster analysis,the tested rice varieties were divided into different groups based on grain yield and CH4emission.Among the50varieties,Huanghuazhan,Wuyou308,Fenghuazhan,Tesanai,Molizhanxuan,Guangchaosimiao,Zhenguiai,Guanghui998,and Qiguizao25were classified into the groups of high yield with low emission,high yield with moderate emission,or moderate yield with low emission.Furthermore,Huanghuazhan and Wuyou308are the mega varieties in South China,whereas Guanghui998is the restorer line for many hybrid rice varieties widely grown in South China.Correlation analysis indicated that the plant height and leaf area index were correlated significantly and positively with CH4emission.Thus,these two traits would be the important indices for screening varieties with high yield and low CH4emission in rice breeding.Furthermore,there was an insignificant correlation between grain yield and CH4emission,suggesting that it is possible to breed new varieties with both high yield and low CH4emission.