Transgenic and genome-edited fruits: background, constraints, benefits, and commercial opportunities

Breeding has been used successfully for many years in the fruit industry,giving rise to most of today’s commercial fruit cultivars.More recently,new molecular breeding techniques have addressed some of the constraints of conventional breeding.However,the development and commercial introduction of such novel fruits has been slow and limited with only five genetically engineered fruits currently produced as commercial varieties—virus-resistant papaya and squash were commercialized 25 years ago,whereas insect-resistant eggplant,non-browning apple,and pink-fleshed pineapple have been approved for commercialization within the last 6 years and production continues to increase every year.Advances in molecular genetics,particularly the new wave of genome editing technologies,provide opportunities to develop new fruit cultivars more rapidly.Our review,emphasizes the socioeconomic impact of current commercial fruit cultivars developed by genetic engineering and the potential impact of genome editing on the development of improved cultivars at an accelerated rate.

Candidate genes underlying QTL for flowering time and their interactions in a wide spring barley(Hordeum vulgare L.) cross

Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that determine a plant's response to these environmental signals are well characterized, the combinatorial effect on flowering time of allelic variants for multiple genes remains unresolved. This study investigated the genetic control of flowering-time in a biparental population of spring barley, derived from a wide cross between a late-flowering European and an early-flowering North-American cultivar. While the major flowering time genes are not segregating in the Beka ×Logan cross, large variation in flowering was observed. We identified five QTL, with both parents found to contribute early alleles. The catalog of QTL discovered aligns with several candidate genes affecting flowering time in barley. The combination of particular alleles at HvCEN, HvELF3 and HvFT1 in Logan are responsible for the earliness of this cultivar. Interestingly, earliness for flowering could be further enhanced, with Beka found to contribute three early alleles, including a QTL colocating with a HvFD-like gene, suggesting that there are diverse aspects of the flowering-time pathway that have been manipulated in these two cultivars. Epistatic interactions between flowering-time QTL or candidate genes were observed in field data and confirmed under controlled conditions. The results of this study link photoperiod-dependent flowering-time genes with earliness per se genes into a single model, thus providing a unique framework that can be used by geneticists and breeders to optimize flowering time in barley.

Organic practices and gender are effective strategies to provide healthy pork loin

This study evaluated the influence of husbandry（organic feed and management but not free-ranging vs. conventional） and sex（barrows vs. gilts） on pork meat quality. A total of 60 Longissimus thoracis pork muscle samples from different 3-way crossbred genotypes were chosen from 3 conventional and 2 organic pig farms. Technological meat quality was measured at 24 h post-mortem and muscle fatty acid content and composition was analysed by gas chromatography. The loin from organic pigs at 24 h of retail display had lower pH, but it had no detrimental effects on drip loss. All the International Commission on Illumination colour attributes except meat lightness differed between husbandry systems. Moisture and crude protein content were lower whereas intramuscular fat content was greater in organic than in conventional pork. Total saturated fatty acid（SFA）, monounsaturated fatty acid（MUFA）, polyunsaturated fatty acid（PUFA） and PUFA n-6 contents did not differ between husbandry systems, but total PUFA n-3（mainly C18：3 n-3） were greater in organic than in conventional pork. Sex did not affect ultimate p H or meat colour attributes but barrows showed lower moisture and greater intramuscular fat than gilts. Total SFA and MUFA content were similar but all the PUFA（both n-6 and n-3） were lower in barrows than in gilts. These results suggest that some bioactive compounds from dietary origin, i.e., linolenic acid（C18：3 n-3） content from dietary vegetable oils（soybean or olive olein）, might be used to highlight the nutritive value of（not free-ranging） organic pork meat. In addition, gilts were leaner than barrows and showed a more favourable PUFA/SFA ratio.