摘要
【目的】探明不同砧木对西瓜根、茎、叶和果实等不同部位镉的积累规律,不同砧木对西瓜果实品质的影响,评价嫁接西瓜生产的安全性,筛选低积累高品质嫁接砧木。【方法】以‘早佳8424’为接穗,以‘野郎’‘西嫁强生’等8个品种为砧木,采用顶插接的方法,爬地栽培,2蔓整枝,留1果。果实成熟后测定根、不同部位茎、叶和果实镉含量,测定单瓜质量、果型指数、中心糖和边糖含量等品质性状。【结果】不同砧木嫁接西瓜植株各部位茎叶镉的积累规律为基部>中部>上部,西瓜果实镉含量低于食品安全国家标准食品中污染物限量GB 2762—2012规定的0.05 mg·kg^(-1),通过对果实镉含量和品质的测定,初步筛选出T1和T5在降低西瓜果实镉含量的同时,增产效果显著。【结论】不同砧木对西瓜镉的积累规律与实生苗相比存在差异,葫芦砧木增加了果实中的镉含量,因此应根据生产需要选择高积累或低积累砧木用于生产。
[Objective]Watermelon （Citrullus lanatus） is loved by people because of its juicy and sweet interior flesh, especially in summer. Watermelon has long been and widely cultivated in Hunan, with about 140 000 hm2 planting area per year, ranking the 4th in China. Because of the considerable economic bene- fits, watermelon is becoming an important horticultural crop in the province. Along with the adjustment of crop structure in heavy metal contaminated areas in Hunan province, trials of watermelon planting in these areas are underway. For sustainable development of local industry, it is important to use proper root- stocks. Studies of the characters of cadmium （Cd） accumulation in grafted watermelon are necessary for sustainable development of watermelon industry in heavy metal polluted areas. [ Methods] We used top plug for grafting, ＇8424＇ as the scion, and eight rootstocks including 3 ＇Yelang＇ lines （T1-T3）, ＇Qiangzhen 1＇ （T4）, ＇Xijiaqingsheng＇ （T5）, ＇Jingxinzhenwang＇ （T6）, ＇ Qingpingtiemujia＇ （TT） and ＇ nuangjindadang＇ （T8）. The grafted plants were trained into a 2-truss trellis system with each truss bearing one fruit. When fruit ripened, cadmium contents in root, stems at different positions, leaves and fruit were mea- sured, and data of single fruit weight, fruit shape index, and quality traits were collected. [Results]The results showed that root Cd content in different rootstocks had significant difference. T5 and T8 roots had a cadmium content 32.6% and 36.9% lower than the non-grafted plants, respectively. Cd content in T4 root was 0.109 mg· kg-1, 77.7% higher than the seedling roots. The basal stem in grafted watermelon plants had a Cd content in the range of 0.028 6-0.086 6 mg·kg-1, i.e. 27.9%-84.4% of that of the seedlings （0.102 6 rag＂ kg-~）, and Cd content in T2, T3 and T5 was the lowest, being 0.043, 0.038 6 and 0.028 6 mg· kg-1, respectively. However, the Cd content in the central stem of T4 rooted plants increased significantly compared to the self-rooted seedlings, while that in those on other stocks was lower than in the seedlings at varying degrees. The Cd content in the central leaves in T1, T2 and T5 rooted plants was 54%, 55.7 and 54% lower than in the seedlings, respectively. The Cd content in the upper stems was different among rootstocks. In T4, it was 0.047 mg·kg-1. Other rootstocks reduced the Cd content in the upper stems at various degrees, and reduction in T5 was the largest, followed by those in T1 and T8. There were significant differences between the self-rooted seedlings and plants on different rootstocks in leaf Cd content. In T4, the basal leaf Cd content reached up to 0.3 mg· kg-1 and was significantly higher than in the self-rooted seed- lings. In T1, T2 and T5, the basal leaf Cd content was 0.06, 0.068, and 0.057 mg· kg-1 lower compared to that in the seedlings, respectively. In T4, the Cd content in the central leaves was 0.233 mg· kg-1, and significantly higher than that in the seedlings, while in plants on other rootstocks, Cd content in the central leaves was reduced at different degrees compared with that in the self-rooted seedlings. T 1, T2 and T3 were 70%, 70% and 68% lower, respectively. The effects on Cd content in the upper leaves differed according to rootstocks. For example, T3 and T4 significantly increased but others reduced it. Among them, the decrease in T5 was the greatest. Different grafting combinations displayed influence on Cd content in the fruit. T1, T2 and T5 reduced it by 60.5%, 61.3% and 60.5% respectively, while T4 increased it by 41.6% compared with the self-rooted control. Among different treatments, the highest Cd content in fruit was 0.006 4 mg·kg-1, lower than the limitation of 0.05 mg· kg -1 defined by GB 2762--2012. Rootstocks also showed influence on fruit weight. T2 and T6 had a lower fruit weight than the control, but the difference was not significant. Fruit weight in T5 increased significantly and reached 5.79 kg. T2 and T3 greatly influenced fruit shape index, but others showed no influence. Rootstocks affected skin thickness, and the effect was significant in T1 and T4. T5 had the highest sugar content （10.53%） in central fruit tissue. T4 had the highest sugar content （8.03%） in side fruit tissues , and T2 had the lowest value of 6.07%. [Conclusion ] Under Cd stress, grafted watermelon on different rootstocks had different Cd absorption capacity and Ca distribution among organs. The Cd content in different plant positions followed a descending order of base〉middle〉 upper part. In root, Cd content is influenced by rootstock genotypes. Our results showed that T1, T2 and T5 had the lowest fruit Cd content and T1 and T5 significantly reduced the Cd content in all plant parts and improved fruit weight with no significant effect on fruit quality. These rootstocks could be suitable for grafted watermelon planted in heavy metal polluted areas.
出处
《果树学报》
CAS
CSCD
北大核心
2017年第10期1309-1315,共7页
Journal of Fruit Science
基金
河南省果树瓜类生物学重点实验室开放基金(HNS-201508-08)
西甜瓜产业技术体系(CARS-26-09)
湖南省青年人才联合培养基金(14JJ6070)
关键词
西瓜
砧木
镉
积累规律
品质
Watermelon
Rootstock
Cadmium
Accumulation trend
Quality
