Evaluating bread wheat varietal responses to late-spring frost conditions

This study investigates the impact of late-spring Frost (LSF) stress on
wheat (Triticum aestivum) during critical reproductive stages. A factorial
experiment was conducted with three wheat genotypes ('Roshan',
'Falat', and 'Superhead'), three growth stages (pollen
development, spike emergence, and pollination), and three stress levels
(normal, one-day stress, and four-day stress) in a completely randomized
design with nine replications. Analysis of variance and mean comparison
(LSD method) showed that wheat varieties responded differently to growth
stages and stress durations, with 'Roshan' being more sensitive
and 'Superhead' more adaptable. Proline accumulation and
increased photosynthetic pigment levels were identified as stress
resistance mechanisms, though they did not fully prevent yield reductions.
Principal Component Analysis (PCA) explained 75.42% of the variation,
showing negative correlations between yield-related traits (grain number
and grain weight) and the first component, while chlorophylls,
carotenoids, and proline correlated positively. These results emphasize
the importance of understanding varietal differences in LSF tolerance and
the need for phenotyping and genetic improvements to develop cold-tolerant
wheat varieties. The findings highlight the vulnerability of reproductive
stages and the importance of targeted breeding strategies to enhance crop
resilience and ensure yield stability in climates affected by LSFs.

本研究探究了晚春霜冻（Late-spring Frost, LSF）胁迫对普通小麦（Triticum aestivum）关键生殖生长期的影响。本研究采用完全随机设计开展析因试验，设置3个小麦基因型（'Roshan'、'Falat'、'Superhead'）、3个生育时期（花粉发育期、穗抽出期、授粉期）与3个胁迫梯度（正常生长、1天胁迫、4天胁迫），每个处理设置9次重复。方差分析与均值比较（最小显著差法，LSD）结果显示，不同小麦品种对生育时期及胁迫时长的响应存在显著差异，其中'Roshan'敏感性更强，'Superhead'适应性更优。脯氨酸积累与光合色素水平提升被鉴定为低温胁迫抗性机制，但二者未能完全阻止产量下降。主成分分析（Principal Component Analysis, PCA）解释了75.42%的总变异，结果显示产量相关性状（粒数与粒重）与第一主成分呈负相关，而叶绿素、类胡萝卜素及脯氨酸则与第一主成分呈正相关。上述研究结果强调了解析小麦品种晚春霜冻耐性差异的重要性，同时指出需通过表型鉴定与遗传改良培育耐低温小麦品种。本研究同时凸显了生殖生长期的作物脆弱性，以及制定针对性育种策略以提升作物抗逆性、保障晚春霜冻频发气候下产量稳定性的必要性。