Plant regeneration from protoplasts isolated from primary calli using mature embryos of two Brazilian rice cultivars

A plant regeneration system from rice protoplasts using calli derived from mature embryos was established for the two Brazilian modern rice cultivars IAC-201 and IAC-165. After 30 to 40 days of in vitro culture it was possible to obtain on average 6 million protoplasts per gram of callus. Microscopic selection of embryogenic calli was a key step for protoplast isolation. The production of embryogenic calli increased when L-proline and casein hydrolysate were used in the callus induction medium. The Oc or IR52 nurse cell lines were essential for protoplast division. Different regeneration media were studied and 139 plants were regenerated which set seed. Some of the regenerated plants showed morphological variation such as the presence of awns in spite of the short time of the in vitro culture. This revised version was published online in July 2006 with corrections to the Cover Date.     

籼型血缘对籼粳稻杂交后代产量和加工及外观品质的影响

针对20世纪80年代以来特别是进入新世纪我国东北水稻大多通过籼粳稻杂交育成的实际情况,为了明确籼型血缘对东北水稻产量和品质的影响,以Sasanishiki(粳稻)/Habataki(籼稻)//Sasanishiki///Sasanishiki构建的回交重组自交系群体(BILs) 85个株系为试材,分别在辽宁沈阳、吉林长春和黑龙江哈尔滨种植,以籼型频率(Fi)即来自籼型亲本分子标记比例为指标,分析了籼型血缘与产量和品质的关系。结果表明, BILs群体在辽宁、吉林和黑龙江能够正常成熟,株系数和Fi平均值有自南向北逐渐降低的趋势,三地生物产量、经济系数和经济产量差异均未达到显著水平(黑龙江生物产量和经济系数缺失);穗数在辽宁、吉林>在黑龙江,每穗粒数在黑龙江>在吉林>在辽宁;糙米率在黑龙江显著高于辽宁,而在吉林与辽宁和黑龙江差异不显著;精米率和整精米率在辽宁、吉林>在黑龙江,垩白粒率和垩白度在辽宁>在吉林>在黑龙江,三地粒长、粒宽和长宽比均无显著差异。总体上Fi与千粒重、经济产量、经济系数、糙米率和粒宽呈极显著负相关,与长宽比呈极显著正相关;三地Fi与产量及其构成因素的相关性与总体相似,只是在黑龙江大多没有达到显著水平;在辽宁和吉林Fi与粒宽呈显著负相关,而只有在辽宁Fi与长宽比的正相关达到显著水平。在本试验条件下,控制籼型频率在10%左右可能有利于实现籼粳亚种有利基因互补,促进东北粳稻产量和品质在更高水平上统一起来。     

水稻籼粳杂种一代稻米加工和外观品质性状研究

采用不同稻米品质3个粳稻和4个籼稻按完全双列模型设计进行杂交，配组了24个籼粳杂种一代F1，对其主要稻米加工和外观品质性状进行研究。加工品质中糙米率和精米率均接近粳稻品种，与籼稻无关，无胞质效应；整精米率差异很大，但大多介于籼粳双亲之间，并且随粳稻亲本不同，其胞质效应表现不一致。外现品质中垩白度和透明度，大多数介于双亲之间．而垩白率多倾向于亲本的高值。     

Comparison of fertility between the F1, F2 and anther derived lines in the crosses of indica/japonica and japonica/indica in rice (Oryza sativa L.)

Summary Response of anthers in in vitro culture was examined in the indica-japonica hybrids of rice (Oryza sativa L.). Significant genotypic differences were observed for callus induction and regeneration among the different interracial hybrids of indica-japonica races. Induction frequency of haploids ranged from 57.7 to 72.9 per cent and doubled haploid androgenic lines ranged from 27.1 to 42.3 per cent in the anther culture of the different hybrids. The indica-japonica hybrids recorded partial pollen grain and spikelet fertility in F1 (29.9 to 41.5% and 19.4 to 48.7% respectively) as well as in F2 (42.7 to 50.6% and 37.1 to 54.4% respectively). In contrast, the androgenic doubled haploid lines recorded significant increase and the pollen grain and spikelet fertility was 76.3 and 78.6 per cent respecitively. The results suggested that the sterility barriers for realising genetic recombinants and fixation of fertile homozygous lines in indica-japonica hybridization programme could be overcome through F1 anther culture technique.Abbreviations BAP Benzyl Amino Purine - 2,4-D 2,4-Dichlorophenoxy acetic acid - MS Murashige & Skoog medium - IAA Indole Acetic Acid