Muthusamy Vignesh, Hossain Firoz, Thirunavukkarasu Nepolean, Choudhary Mukesh, Saha Supradip, Bhat Jayant S, Prasanna Boddupalli M, Gupta Hari S
Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India.
Division of Agricultural Chemicals, ICAR-Indian Agricultural Research Institute, New Delhi, India.
PLoS One. 2014 Dec 8;9(12):e113583. doi: 10.1371/journal.pone.0113583. eCollection 2014.
Development of vitamin A-rich cereals can help in alleviating the widespread problem of vitamin A deficiency. We report here significant enhancement of kernel β-carotene in elite maize genotypes through accelerated marker-assisted backcross breeding. A favourable allele (543 bp) of the β-carotene hydroxylase (crtRB1) gene was introgressed in the seven elite inbred parents, which were low (1.4 µg/g) in kernel β-carotene, by using a crtRB1-specific DNA marker for foreground selection. About 90% of the recurrent parent genome was recovered in the selected progenies within two backcross generations. Concentration of β-carotene among the crtRB1-introgressed inbreds varied from 8.6 to 17.5 µg/g - a maximum increase up to 12.6-fold over recurrent parent. The reconstituted hybrids developed from improved parental inbreds also showed enhanced kernel β-carotene as high as 21.7 µg/g, compared to 2.6 µg/g in the original hybrid. The reconstituted hybrids evaluated at two locations possessed similar grain yield to that of original hybrids. These β-carotene enriched high yielding hybrids can be effectively utilized in the maize biofortification programs across the globe.
富含维生素A的谷物的开发有助于缓解普遍存在的维生素A缺乏问题。我们在此报告，通过加速标记辅助回交育种，在优良玉米基因型中显著提高了籽粒β-胡萝卜素含量。利用β-胡萝卜素羟化酶（crtRB1）基因的一个有利等位基因（543 bp），通过一个crtRB1特异性DNA标记进行前景选择，将籽粒β-胡萝卜素含量低（1.4 µg/g）的7个优良自交系亲本导入该等位基因。在两个回交世代内，所选后代中约90%的轮回亲本基因组得以恢复。导入crtRB1的自交系中β-胡萝卜素浓度在8.6至17.5 µg/g之间变化，比轮回亲本最高增加了12.6倍。与原始杂交种中2.6 µg/g相比，由改良亲本自交系培育的重组杂交种籽粒β-胡萝卜素含量也提高到了21.7 µg/g。在两个地点评估的重组杂交种的籽粒产量与原始杂交种相似。这些富含β-胡萝卜素的高产杂交种可有效地用于全球的玉米生物强化计划。
