Current progress in application of 1-Methylcyclopropene to improve postharvest quality of cut flowers

Floral senescence or petal abscission that determine cut flower quality and longevity are primarily caused by the regulation of endogenous ethylene and perception of endogenous and exogenous ethylene in floral organs(such as the petals and gynoecium),in ethylene-sensitive species.Several attempts have been made to prolong flower quality and longevity using silver ions and other chemicals that inhibit ethylene production and perception in floral organs.Among the available compounds,1-methylcyclopropene(1-MCP)has been increasingly used as ethylene-action/perception inhibitor because of its ability to inhibit ethylene action/perception and it is environmentally safe.Although 1-MCP has been used in several cut flower crops for about 25 years,there has been no review yet that critically emphasizes the benefits or difficulties of using this compound for the prolongation of cut flower quality and longevity.Here,we outline the role of 1-MCP in inhibiting ethylene action/perception and petal senescence in cut flowers through the blocking of receptor binding sites,and we discuss how various factors affecting efficacy of 1-MCP(such as concentration,treatment time and temperature,genotype,and flower stage)are involved in the achievement of flower longevity.Moreover,we highlight the advantages of applying nonvolatile and liquid 1-MCP formulation types,as opposed to using the conventional 1-MCP treatment(powder formulation type).We expect that this review will provide useful information for the future utilization of 1-MCP for the maintenance of cut flower longevity.

Identification of Quantitative Trait Loci （QTLs） Determining Flowering in the Robusta Coffee （Coffea canephora Pierre）

The quantitative trait loci （QTLs） analysis for flower traits were performed based on three crossing of Coffea canephora in Indonesia. This study successfully identified 19 QTLs related to flowering. These QTLs consisted of 1） three QTLs associated with green candle flowering time located at linkage groups of A and D; 2） one QTL associated to white candle flowering time located at linkage groups of B; 3） two QTLs associated to blossom flowering time located at linkage groups of B; 4） two QTLs associated to number of flowers located at linkage groups of G and H; 5） five QTLs associated to score of flowers quality located at linkage groups of A, C and D; 6） five QTLs associated to number of star flowers located at linkage groups of D, E, F and G. Due to some QTLs are overlapping on the same linkage group, thus, these 19 QTLs for flower traits might be considered as 15 different ones which distributed on 14 regions of the eight linkage groups. Although pleiotropic genes might be the most likely explanation for the collocation of these QTLs, the present data are not sufficient to distinguish between a pleiotropic gene and a cluster of different loci controlling several traits. These results can be a first step for molecular breeding on Robusta coffee mainly in order to improve potential suitable characteristics such as number of flowers and number of normal flowers as well as to reduce adverse characteristics such as number of star flowers.

Biofumigation Efficacy of Spider Plant (Cleome gynandra L.) Accessions on Nematode Control in Tuberose (Polianthes tuberosa L.)

Tuberose(Polianthes tuberosa L.)is a perennial summer flower grown by smallholders in Kenya for export.However,its production and export volumes have declined drastically due to nematodes infestation.This study evaluated the effect of Cleome gynandra accessions on nematode management on tuberose.Experiment was carried out at Egerton University,Kenya using a randomized complete block design with four replications.The treatments were C.gynandra namely“Simlaw”,“Egerton”,“Taastrup”,“PS”and“IP8”,applied at 6 kg/m^(2) and compared with Brassica napus,solarization and untreated control.Data was collected on growth and yield parameters,nematode infestation and quality of tuberose.Data collected was subjected to analysis of variance at p≤0.05 and means separated using Tukey’s test.Biofumigation with Cleome gynandra accessions helped to reduce nematode population by 34%,gall numbers by 83% and galling index by 96%when compared with the control.Use of biofumigation helped to improve plant height and leaf number of tuberoses by 16% and 87%,respectively,when compared with the control.Use of biofumigation helped to improve spike length by 32%,marketable spikes by 80%,and flower yield by 90% and reduced nonmarketable spikes by 95% when compared with the control.Based on the above results,use of Cleome gynandra accessions and other biofumigants such as rape seed can be used to manage nematodes and improve growth,yield and quality of tuberose.

Differential expressions among five Waxy alleles and their effects on the eating and cooking qualities in specialty rice cultivars

Eating and cooking qualities（ECQs） of rice are important attributes due to its major influence on consumer acceptability. To better understand the molecular mechanism of the variation in ECQs, we investigated and compared the expressions among different alleles of the Waxy（Wx） gene and its effect on ECQs in specialty rice cultivars. The results showed that the accumulation of amylose was positively and significantly correlated to the level of mature Wx m RNA and granule-bound starch synthase I（GBSS I） in developing rice grain at 12 days after flowering. The amount of GBSS I and its activity together are the main factors controlling amylose synthesis. Differences in ECQs among five Wx allele types were investigated in samples from 15 rice varieties. The apparent amylose content（AAC） and gel consistency（GC） were similar in each type of Wx allele. The AAC followed the order, Wx^a type〉Wx^in type〉Wx^b type〉Wx^mq type〉wx. Contrary to this, the GC showed an opposite trend compared to AAC. There was a wide variation in rapid visco analyzer（RVA） profile among five Wx allele types, while varieties sharing a specified Wx allele had basically the similar RVA profile, although there was a slight difference in some RVA parameters, peak, hot paste and cool paste viscosities.

Effects of different growing media on the cut flower performances of oriental two Lilium varieties

In this study,six different growing media(peat+pumice:1:1,v/v;peat+perlite:1:1,v/v;rice hull+pumice:1:2,v/v;coarse sand+peat:2:1,v/v;soil;and cocopeat)were evaluated for their effects on the plant growth and flower quality of the oriental‘Siberia’and‘Vespucci’lily varieties.Seven hundred and twenty bulbs were planted in perforated plastic crates and placed in an unheated greenhouse.The physical and chemical properties of the growing media were examined.The number of days to flowering,plant height,the number of flowers,fresh stem weight,the number of leaves and vase life were investigated in the study.The results indicated that the use of soilless growing media significantly affected plant growth and flower quality when compared with soil.The obtained values varied by substrate type.The earliest flowering time(154.78 d)and the longest plant height(120.82 cm in the‘Siberia’variety)were determined in peat+pumice,whereas the largest number of flowers(7 flowers in Siberia;5.67 flowers in Vespucci)and the highest stem weight(266.13 g in Vespucci;353.91 g in Siberia)were recorded in cocopeat.The vase life of the plants grown in soil was longer than that of the plants grown in the soilless culture.Regarding the number of leaves,rice hull+pumice(57.42 leaves)and sand+peat(54.46 leaves)gave the best results.