Abstract：
Sweet corn has emerged as a favorite food item worldwide owing to its kernel sweetness. However, traditional sweet corn cultivars are poor in provitamin-A (proA) and essential amino acids, viz., lysine and tryptophan. So far, no sweet corn hybrid with high nutritional qualities has been commercialized elsewhere. Here, we analyzed accumulation of provitamin-A (proA), lysine, and tryptophan in a set of mutant versions of (i) crtRB1-, (ii) o2-, and (iii) crtRB1 + o2-based sweet corn inbreds and hybrids with (iv) traditional sweet corn (wild-type: O2 + CrtRB1). The crtRB1- and crtRB1 + o2-based genotypes possessed significantly higher proA (17.31 ppm) over traditional sweet corn (2.83 ppm), while o2- and crtRB1 + o2-based genotypes possessed significantly higher lysine (0.345%) and tryptophan (0.080%) over traditional sweet corn (lysine 0.169%, tryptophan 0.036%). Late sowing favored high kernel lysine, proA, and green cob yield among hybrids. Sweetness (17.87%) among the improved inbreds and hybrids was comparable to the original sweetcorn genotypes (17.84%). Among the four genotypic classes, crtRB1 + o2-based improved genotypes showed stronger association among traits over genotypes with o2 and crtRB1 genes alone. Significant association was observed among (i) proA and BC (r = 0.99), (ii) proA and BCX (r = 0.93), (iii) lysine and tryptophan (r = 0.99), and (iv) green cob yield with fodder yield (r = 0.73) in sweet corn hybrids. The study demonstrated that combining crtRB1 and o2 genes did not pose any negative impact on nutritional, yield, and agronomic performance. Sweet corn with crtRB1 + o2 assumes significance for alleviating malnutrition through sustainable and cost-effective approach.
摘要：
甜玉米由于其籽粒的甜味而成为全球最受欢迎的食品。然而,传统甜玉米品种维生素原A（proA）和必需氨基酸含量低，viz.,赖氨酸和色氨酸.到目前为止,没有高营养品质的甜玉米杂交种在其他地方商业化。这里,我们分析了维生素原A（proA）的积累，赖氨酸，和色氨酸在一组突变版本的(I)crtRB1-，(ii)o2-，和（iii）基于crtRB1o2的甜玉米自交系和与（iv）传统甜玉米（野生型：O2CrtRB1）的杂种。基于crtRB1和crtRB1o2的基因型比传统甜玉米（2.83ppm）具有明显更高的proA（17.31ppm），而基于o2-和crtRB1+o2的基因型具有显著高于传统甜玉米(赖氨酸0.169%)的赖氨酸(0.345%)和色氨酸(0.080%)，色氨酸0.036%)。晚播有利于高赖氨酸，proA,杂种中的绿色穗轴产量。改良的自交系和杂种的甜度（17.87％）与原始甜玉米基因型（17.84％）相当。在四个基因型类别中，与单独使用o2和crtRB1基因的基因型相比，基于crtRB1的改良基因型在性状之间显示出更强的关联。在（i）proA和BC（r=0.99）之间观察到显着关联，(Ii)proA和BCX(r=0.93)，（iii）赖氨酸和色氨酸（r=0.99），（iv）甜玉米杂交种的绿色玉米芯产量与饲料产量（r=0.73）。研究表明，crtRB1和o2基因的结合对营养没有任何负面影响，产量，和农艺表现。含crtRB1+o2的甜玉米对于通过可持续和具有成本效益的方法减轻营养不良具有重要意义。
