Comparison Of Forage Yield And Feeding Value In Maize-teosinte Hybrids F₁

In order to provid theoretical evidence for high yield and high quality forage selected by crossing maize with teosinte, the crossability between maize and teosinte, and heterosis of the maize-teosinte hybrids F1 were explored while the maize-teosinte hybrids and their parents were used as materials. In addition, the effect of plant density on yucao 2 was investigated in the study. The main results were as follows:1 The crossability between maize and teosinte, the meiosis and pollen fertility of the maize-teosinte hybrids F1 were investigated. The results shown that the chromosome pariring configuration in meiosis diakinesis per pollen mother cell (PMC) of Z. mays×Z. Mexicana, Z.mays×Z. parviglumis, Z.mays×Z. huehuetenangensis, Z.mays×Z. diploperennis, Z.mays×Z. nicaraguensis, Z. mays×Z. luxurians and Z.mays×Z.perennis was 0.080Ⅰ+9.960Ⅱ,0.267Ⅰ+9.867Ⅱ,0.573Ⅰ+9.713Ⅱ,0.667Ⅰ+9.667Ⅱ, 0.747Ⅰ+9.627Ⅱ,0.760Ⅰ+9.620Ⅱand 4.773Ⅰ+5.173Ⅱ+4.960Ⅲ, respectively. The chromosome relative chaotic coefficient in meiosis of hybrids F1 was 0.004,0.014,0.030,0.034,0.039,0.040 and 1.899, respectively. The pollen fertility of hybrids F1 was 92.51%,90.69%,83.33%,75.46%,67.08%, 65.57%and 17.66%, respectively. The teosinte can be directly crossed with maize, and the hybridization seed rate had highly significant deviation. In conclusion, the information on pollen fertility and chromosome relative chaotic coefficient appearanced a close relationship, which is useful in the assessment of genetic relationships. The meiosis behaviors and pollen fertility of Z. mays-Z. nicaraguensis hybrid was first reported in this study, supposed that Z. nicaraguensis discovered recently was more genetically closer to Z. luxurians than to other teosintes.2 The forage yield, yield characters and feeding value heterosis of maize-teosine hybrids were investigated. The results shown that high levels of heterosis were obtained in the hybrids F1 between maize and teosinte based on two years data. For forage yield and yield traits, the fresh matter yield and dry matter yield had the highest heterosis level, the average heterosis was 0.9623 and 0.8095, respectively, and the area of the reciprocal fourth leaf, total stem perimeter and main stem perimeter took second place, the average heterosis was0.6203,0.3824 and 0.2941, respectively, and the grass length, tiller and green leaves had the lowest heterosis, the average heterosis was0.1541,0.1328 and 0.0560, respectively. The heterosis of feeding composition yield characters was higher than feeding composition content characters. The hybrids between maize and Z. nicaraguensis, Z. huehuetenangensis had the relative higher forage yield and feeding value heterosis. Moreover, the research revealed initial tasseling stage of maize-teosinte hybrids F1 were earlier than teosinte. The result indicated that it could improve the forage yield and feeding value by distant hybridization between maize and teosintes.3 The fresh yield of single plant and yield traits among 14 maize-teosinte hybrids F1 were investigated The main results were that forage yield and yield traits per plant had significant or highly significant deviation, except for the total stem perimeter, and the coefficient of variation (CV) of fresh yield of single plant was the highest (47.30%). Fresh yield of single plant was negatively associated with tiller, significantly positively associated with main stem perimeter, and highly significantly positively associated with grass length, green leaves, total stem perimeter and area of the reciprocal fourth leaf. The order of direct effect on fresh yield of single plant from large to small was grass length, tiller, total stem perimeter, green leaves and area of the reciprocal fourth leaf. The result indicated that the grass length was an important character for improvement of fresh yield of single plant of maize-teosinte hybrids F1.4 The main result of the feeding value traits among 14 maize-teosinte hybrids F1 indicated that all the feeding value traits had highly significant variation, and the CV of EE was the highest (30.37%). The correlation analysis of quality traits among maize-teosinte hybrids F1 showed that in vitro dry matter digestibility (IVDMD) had a highly significant negative correlation with acid detergent lignin (ADL), acid detergent fiber (ADF) and neutral detergent fiber (NDF), but a highly significant positive correlation with crude protein (CP)and ether extract (EE). The order of the traits influencing forage from large to small was NDF, IVDMD, ADF, CP, ADL and EE.5 The plant density experiment of yucao 2 main results were as follows:The fresh and dry matter yields of the three forage, which showed the change of "low-high-low" with the increase of planting density, and the optimum plant density was 75000,75000 and 52500 plant·hm-2, respectively. The fresh and dry matter yields were the highest in the Yucao 2 and lowest in Zea mexicana among all planting density. The yields of CP, ADF, NDF and EE in Yucao 2 and chuandan14×Zea Mexicana were higher than in Zea mexicana significantly or high significant, however, the content of CP and EE was the highest in Zea mexicana.The Relative feeding value(RFV) in Yucao 2 had no significance with that in Zea mexicana and were higher than in chuandanl4×Zea mexicana significantly. Main component of dry weight was leaves in Zea mexicana, while stems in Zea mays-Zea mexicana hybrids. In conclusion, the differences of matter yield and feeding value among the three forage derived from the significant differences among their biological characteristics.In conclusion, the maize and teosinte were cross-fertile. Both forage yield and feeding value of maize-teosinte hybrids F1 exhibited strong heterosis. The hybrids of Z.mays×Z. nicaraguensis and Z.mays×Z. huehuetenangensis had the relative higher forage yield and feeding value, which indicated that the Z. nicaraguensis and Z. huehuetenangensis were the best pollen parent for maize to select forage breed. The optimum plant density for yu cao 2 was 75000 plant-hm-2.