宿根稻研究的现状和展望

ADVANCE AND PROSPECT OF BREEDING FOR PERENNIAL RICE

柳州野稻和长药野稻是本研究重要的宿根性状来源。已证明：宿根性是显性数量性状。这两个野稻的宿根性１９７７年经种间复交光粳Ａ／柳野∥长野而输入栽培稻，Ｆ１名为４０２０。这个Ｆ１有根状茎且宿根重现性特好，已在成都宿根生长、越冬１９年。成都常年１月平均气温５．４℃，极值－７．６℃。宿根系４０２０正用作主要亲本进一步选育宿根栽培稻。预计，早熟宿根稻６０天收割一次，年收数次使总产大增。宿根旱稻与三叶草间种，免耕，有厚层土表覆盖防水土流失。宿根稻区内有益生物和有害生物间形成自然平衡。从而减少农用化学品的施用。

O.rufipogon with permanent tillering,and O,longistaminata producing strong rhizoma by which the plant perennates,were identified as ideal donors of perenniality that was found to be a quantitatively dominant trait.In 1977,perenniality of those wild germplasms was incorporated into rice cultivars by interspecific crosses of Guangken A/O.rufipogon∥O.longistaminata ,F 1 named as 4020.This hybrid F 1 has rhizoma and excellent perenniality recovery.It grows and overwinters normally,depending on the rhizoma,for 19 years in Chengdu.Where monthly mean temperature in January is 5.4℃,minimum -7.6℃.The 4020 is being used as major parent to develop perennial rice cultivars. We can hypothesize that early perennial rice has no vegetative phase,and duration from emergence to maturity lasts for 60 days.Thus,given the proper conditions around year,several harvests could be perfomed,and maximum rice yield would be obtained.In upland,perennial rice will be interplanted with white clover.They produce a thick permanent ground cover without tillage to prevent soil erosion.There exists a balance among beneficial organisms and pests within the perennial rice growing areas.The use of agricultural chemicals should be reduced.More rice could be produced with less efforts.