| Peanut (Arachis hypogaea L.) is an important oil and commercial crop in China, and it plays an important role in national economy. Germplasm resources are the material basis for peanut breeding, therefore, the evaluation, utilization and innovation of germplasm resources has also been an important content in research of peanuts. In this paper, main agronomic traits of376peanut germplasm resources collected from different regions of China were investigated. On this basis, focing on the pod and yield related traits of peanuts, the comparsion between traditional varieties and improved varieties, and between varieties from the Southern China and those from the Northern was conducted. Likewise, the relationships of different agronomic traits were analyzed. The objectives of this study were to analyze the performances and variations of important agronomic traits among different types of peanut germplasms, to select germplasms with comprehensive or single prominent traits for breeding and genetic research. The main results of this study are as follows.1. The averages of main agronomic traits of376peanut germplasm resources were as follows:13.4d for time from seeding to seedling,41.4d for time from seeding to flowering,132.7d for whole growth period;6.1cm for leaf length,2.9cm for leaf width,1.9cm for leaf’s spacing,7.3cm for petiole length;42.2cm for main stem height,4.8mm for stem diameter,47.2cm for length of the first branch;10.0for total number of branches,6.0for number of first branches,4.0for number of secondary branches;33.3mm for pod length,14.5mm for pod width;16.7mm for kernel length,8.7mm for kernel width;169.9g for100-pod weight,64.2g for100-kernel weight,70.8%for kernel production rate,13.8for number of pods in each plant. Further analysis showed that the coefficient of variation is lower in the traits of whole growth period (6.65%) and kernel production rate (6.64%), but higher in the traits of number of secondary branches (87.5%), total number of branches (44%), number of first branches (28.1%) and number of pods in each plant (41.3%). Variation coefficients were around30%in the traits of100-pod weight,100-kernel weight, stem height and the length of the first branch, and10.0-20.0%for other traits.2. Further comparison of traditional varieties and improved varieties in pod and yield-related traits were conducted. The averages of related traits of local varieties were as follows:30.1mm for pod length,13.4mm for pod width;15.1mm for kernel length,8.3mm for kernel width;135.4g for100-pod weight,50.6g for100-kernel weight,71.7%for kernel production rate,12.6for number of pods in each plant. However, the averages of related traits of bred varieties were as follows:36.2mm for pod length,15.5mm for pod width;18.3mm for kernel length,9.1mm for kernel width;197.1g for100-pod weight,74.9g for100-kernel weight,71.3%for kernel production rate,15.7for number of pods in each plant. Compared to the local varieties, the aboved traits (except the kernel production rate) of the breds were significantly higher than those of local varieties, but the coefficients of variation of bred varieties were less than those of local varieties. These results indicated that the traits of pod and yield in bred varieties are significantly improved but genetic background narrow.3. Further comparison of varieties from the Southern China and those from The northern in pod and yield-related traits were conducted. The averages of related traits of southern varieties were as follows:32.6mm for pod length,14.7mm for pod width;16.4mm for kernel length,8.5mm for kernel width;168.4g for100-pod weight,62.7g for100-kernel weight,70.9%for kernel production rate,14.6for number of pods in each plant. However, the averages of related traits of northern varieties were as follows:36.8mm for pod length,15.7mm for pod width;18.9mm for kernel length,9.4mm for kernel width;203.4g for100-pod weight,80.4g for100-kernel weight,71.4%for kernel production rate,16.5for number of pods in each plant. Compared to the northern varieties, the aboved traits (except the kernel production rate and number of pods in each plant) of southern varieties were significantly lower than those of northern varieties. but no significant difference in the coefficients of variation between southern and northern varieties.4. Correlation analysis of agronomic traits showed that the highest correlation coefficient was in traits of100-pod weight and100-kernel weight (r=0.9108). The higher correlation coefficients were also existed among100-pod weight and100-kernel weight with pod length, pod width, kernel length and kernel width, respectively, which indicated that the varieties with bigger pods usually had heavier pod and kernel production. We also found that the varieties with higher stem usually had longer first branch, and the varieties with higher total number of branches had hiher number of first branches. However, the trait of kernel production rate had no significant correlation with other traits, indicating it is a trait with independent inheritance.5. The results showed that there are great differences in traits of germplasms. For example, the heaviest100-pod weight of peanut is363.7g, while the lightest is only49.7g. The heaviest100-kernel weight of peanut is153.6g, while the lightest is only19.2g. The longest of pod length of peanut is48.1mm, while the shortest is15.2mm. The longest kernel length of peanut is32.0mm, while the shortest is7.8mm. The resuts indicated that these specific germplasm have laid a good foundation for the innovation of germplasm and genetic study. Meanwhile, according to different breeding objectives, these resources with specific traits as good gene donors will be used in the future breeding in penuts. |
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