Study On Creating Novel Bread Wheat Germplasm With High-yield And Good-quality Characters By Using Triticum Dicoccoides

In this paper, The F₈ generation derived from the bread wheat cultivar CN16 being crossed by wild emmer (Triticum dicoccoides, AABB, 2n=4x= 28) was suggested. The chromosome number, stripe resistence, agronomic traits like earing period, plant height, spikelets, 1000-grain weight, grain sink, etc., nutrition qualitty including protein, Fe and Zn contents from a total of 1099 lines, were analyzed. And some excellent lines were obtained. The main results are as follows.1. The chromosome numbers in roots in tested materials were stable 42, which is equal to that of T. aestivum(2n=6x=42), by means of the cytogenetical analysis.2. The investigation of agronomic traits showed that novel high-yield germplasm materials with good agronomic traits might effectively be created by distant hybridization between wild emmer and bread wheat. In the tested 1099 lines, 29.03% of lines were in immunity without stripe rust spots. The late earing period from wild emmer was improved due to the earing period in 20.47% and 12.28% of lines being equal to, and earlier than that of CN16, respectively. The bad properties like lodge and fragile spike from wild emmer were observed in more than 50% and 82.89% of tested lines. In addition, the too high character from the parent was improved oweing to 12.11% of lines were in short-stalked and semi-dward plant height in addition to 1.91% of lines being shorter than CN16. The productive ears in 65.85% lines were closed to that of CN16. The spikelets in 70.95% of lines ranged from 20 to 24, as well as the types with 25, 27 spikelets were discovered, of which 71.49% had spikelets over than that of CN16. Majorities of tested lines had high 1000-grain weight because of 1000-grain weight in 55.34% of lines more than that of CN16 (40.01g), of which that of 11.51% overpassed 50g. The grain sinks were outstandingly increased oweing to the trait in all tested lines higher than that of CN16. Yield per plant of 33.76% of lines higher than that of CN16 (15.79g), and some achieved at two times as CN16, and the highest reached 38.58g.3. Nutritional quality traits including protein, micronutrient Fe and Zn contents of F₈ between CN16 and wild emmer were measured. And the results showed that super genes encoding high protein, Fe and Zn contents in wild emmer had been integrated into the genetic background of common wheat. The grain protein contents in all the tested 63 lines, covering the low, middle and senior level of 1000-grain weight, ranged from 11.60% to 19.09% with the mean of 13.20%, and were higher than that of CN16. The Fe contents in 30.16% of lines were higher than that of CN16 (43.67mg/kg), and in 11.11% of materials overpassed 60mg/kg, even in some lines were closed to that of wild emmer. Zn contents in 82.54% lines were higher than that of CN16 (11.82mg/kg), in 30.16% of materials were more than 20mg/kg, even in some lines reached the leave of wild emmer (47.81mg/kg).4. Correlation analysis between agronomic traits in F₈ generation showed that fragile spike was significantly positively related with both plant height and lodge at 0.01 level. The significant positive relationships between plant height and the traits like spikelet number, 1000-grain weight and lodge were discovered at 0.01 level besides that between it and earing period was at 0.05 level. Additionally, spikelet number was significantly positively correlated with earing period at 0.01 level, while negatively with both 1000-grain weight and lodge at 0.05 level.5. The correlation analysis between quality and yield traits in F₈ generation implied that Zn content was significantly positively associated with those of Fe and protein at 0.01 level. 1000-grain weight had to do with the contents of both Fe and Zn significantly negatively at 0.01 level, but without protein content. So, it is possible that the both Fe and Zn contents, or micronutrient and protein contents are synchronously increased by the distant hybridization between wild emmer and common wheat.6. By seletion and comprehensive evaluation, a number of high-yield lines were gotten, which have the good traits with rust stripe, lodging resistance, large storage capacity and suitable height without the properties of fragile spike and late earing period, and so on. Some novel bread wheat germplasms with high-protein and high-Fe, Zn contents, also with good-quality and high-yield characteristic were created. The results suggested that the breeding goal of synchronous improvement of high-yield and high-quality might be realized.